# MPC/TSS custody share: treasury companies, staking, retail/embedded wallets, vendor aggregates, other holders

Research date: 2026-10-29. Companion data file: `custody_tech_treasury_staking_retail.json` (69 entity records, same schema as requested).
Out of scope here (other agent): exchanges' own custody stacks, custodians, ETFs.

**Definitions used.**
- **MPC/TSS**: threshold ECDSA where the full key is never assembled. Examples: Fireblocks MPC-CMP, Copper, Zengo 2P-ECDSA, Dfns, Fordefi, Para, Particle.
- **Not MPC**:
  - Shamir secret sharing with reconstruction (Privy, Web3Auth default tiers, Magic).
  - Single-key TEE wallets (Turnkey, Coinbase CDP v2, Lit v3).
  - HSM/cold custody (Anchorage, Coinbase Custody cold storage).
  - On-chain multisig (Safe, BitGo WalletSimple).
  - Protocol contracts (Lido WithdrawalVault, EigenPods, minipools).
- **Source tags**:
  - **[SEC]**: SEC filing.
  - **[CO]**: company document or blog.
  - **[2ND]**: secondary source (news, tracker, Arkham).
  - **[MKT]**: marketing claim.
  - **[OWN]**: my own on-chain analysis.
  - **[I]**: inference.

---

## 0. Bottom line

1. **BitMine is the largest single swing factor in this scope.**
   - It holds 6.05M ETH (4.95% of supply), of which 5.23M is staked (2026-10-25, [SEC]).
   - Its filings name **no ETH custodian**. They say only "regulated custodians" and "multisignature keys".
   - The one BitMine wallet identifiable on-chain (Arkham label) is a **BitGo WalletSimple contract multisig**, not MPC. It is the withdrawal address of 14 validators (27.7k ETH).
   - My beacon-state census shows only 0.52M ETH, across *all* entities, in consolidated 0x02 validators withdrawing to BitGo WalletSimple contracts. So **most of BitMine's 5.23M staked ETH must withdraw to other, almost certainly EOA, addresses** whose key tech is unknown. Those could be BitGo TSS, Fireblocks or Coinbase Prime MPC, or Anchorage HSM.
   - Best guess 25% MPC; range 0–85%; low confidence.
2. **Staked ETH census** ([OWN], finalized beacon state 2026-10-29: 818,772 validators, 44.24M ETH).
   - About 13M ETH (≈29%) withdraws to protocol contracts (Lido vault 9.54M, ether.fi, Rocket Pool, Liquid Collective, StakeWise, Mantle). These are **0% MPC**.
   - Among the top-400 withdrawal addresses (71% of stake):

     | Withdrawal address type | ETH |
     |---|---|
     | Plain EOAs | 15.29M |
     | EIP-7702-delegated EOAs | 1.39M |
     | Safe | 0.89M |
     | BitGo WalletSimple | 0.58M |

   - MPC can only hide behind EOAs, and **it cannot be distinguished on-chain from HSM or single-key EOAs**.
   - Attributed exchange EOA withdrawal addresses: Binance 3.61M, Kraken 1.78M, OKX 0.69M.
   - Best guess for MPC-vault withdrawal addresses of *non-exchange, non-BitMine* stakers (clients of Figment, Kiln, Blockdaemon, P2P, Twinstake, Chorus who use Fireblocks, Copper, Cobo, Fordefi or BitGo-TSS): **~2.5M ETH (1.0–4.5M)**, low confidence. Fireblocks publishes no absolute staking figure, only "ETH staking volume on our platform has more than doubled in the last six months" (2026-06-11).
3. **Retail and embedded wallets are small for MPC.**
   - The biggest embedded-wallet stacks are *not* MPC: Privy (110M+ wallets, SSS+TEE), Turnkey (TEE), Magic (TEE+KMS), Coinbase CDP v2 (TEE), MetaMask/Web3Auth default tiers (SSS).
   - The trend in 2025–26 is away from MPC:
     - OKX sunset its MPC wallet (Nov 2025).
     - Coinbase deprecated its MPC Server Wallet v1 (2026-02-02).
     - Lit moved to a single-TEE design (v3).
     - Bitget's new login is TEE-based.
   - Real retail MPC: Zengo (~2M users) and Binance Wallet keyless (2-of-3).
   - Order of magnitude **~0.1–0.2M ETH (0.016–0.72M)**.
4. **Fireblocks' "40% BTC / 30% ETH" split** is from Ledger Insights, 2021-07-27, and refers to **March 2021**: "Back in March, the assets under custody were split 40% Bitcoin, 30% Ether and the rest mainly tokenized assets".
   - No absolute AUC was given for that date. Fireblocks' last absolute AUC disclosure is **$45B on 2022-01-27**.
   - Applying the 2021 mix crudely gives ~$13.5B of ETH ≈ 5.6M ETH at ~$2.4k. This is stale, and Fireblocks has published no AUC since.
   - Copper, Cobo, Dfns, Fordefi and Utila publish volume or marketing AUC only, and nothing ETH-specific.
5. **Other holders.**
   - Ethereum Foundation (>160k ETH migrated Oct 2025): Safe multisig, 0% MPC.
   - Galaxy (61k ETH on its balance sheet): Fireblocks licence plus its own GK8 cold vault and uMPC, so mixed.
   - Jump: uses Cordial Systems' MPC "Treasury".
   - B2C2 and GSR: Fireblocks customers. Wintermute: Fireblocks per promotional copy.
   - US government: only ~17k ETH remains (Arkham), with the USMS contract at Coinbase Prime.

**Rough roll-up for this scope** (ETH in MPC/TSS keys; overlaps flagged in §6):

| Segment | ETH base | MPC best guess | Low | High |
|---|---|---|---|---|
| Treasury cos (BitMine) | 6.05M | 1.51M | 0 | 5.1M |
| Treasury cos (others, ex-Ether Machine) | ~1.2M | ~0.09M | ~0.01M | ~0.35M |
| Staking WCs, non-exchange non-BitMine (MPC vault clients of non-custodial providers) | ~5–8M "other institutional" | 2.5M | 1.0M | 4.5M |
| Retail / embedded wallets | n/a | 0.15M | 0.016M | 0.72M |
| Other holders (EF, Galaxy, market makers, US gov) | ~0.25M known | ~0.05M | ~0.0M | ~0.3M (market makers unknown) |
| **Total (this scope)** | | **~4.3M (≈3.5% of 122.2M supply)** | **~1.0M** | **~11M** |

---

## 1. Ethereum treasury companies

### 1.1 Summary table

| Entity | ETH (date) | Staked / providers | Custodians and wallet tech (from filings) | Class | MPC best (low–high), conf. |
|---|---|---|---|---|---|
| **BitMine (BMNR)** | **6,051,933** (2026-10-25) [SEC] | 5,227,037 (86%) via MAVAN (ex-Pier Two, acquired Mar 2026) + unnamed "staking partners" | No ETH custodian named. "regulated custodians" + "multisignature keys"; BTC at BitGo Trust (Gemini backup). Identified wallet = BitGo WalletSimple [OWN/2ND]. 2025 PIPE deck listed FalconX, Kraken, Galaxy as "Custody, Staking and Rails Partners" | Mixed / unknown | **25% (0–85%)**, low |
| SharpLink (SBET) | 888,938 (2026-08-03) [SEC]: 634,255 native + 181,748 via LsETH + 72,935 via weETH | ~100%: native via unnamed third-party validators; Liquid Collective; ether.fi | **Anchorage Digital Bank** + **Coinbase Inc.**; WCs "controlled by our custodian" | HSM/cold custodian + protocol | 1% (0–10%), medium-high |
| Bit Digital (BTBT) | 164,842.2 ETH/LsETH (2026-07-31) [SEC] | 74,174 staked; native via **Figment**; 66,192 LsETH (49k pledged to Galaxy) | **Cactus Custody and Fireblocks** | MPC-heavy, mixed | **45% (20–55%)**, low-medium |
| The Ether Machine (ex-ETHM) | ~495k [2ND trackers]; **SPAC merger terminated 2026-04-08** [SEC] | DARMA (planned) | Pre-closing escrow at Coinbase Custody Trust | Unknown | Unknown (0–20%) |
| BTCS | 54,841 (2026-06-30) [SEC] | 2,880 own validators; ~47.8k in Aave (aEthWETH collateral) | Self-custody, "not held by any third-party custodian"; unnamed wallet-infra provider; "multi-signature authorization, hardware security modules, cold storage" | ~87% protocol + self-custody | 5% (0–13%), low |
| Eightco (ORBS) | 16,278 (2026-10-28) [SEC] | 0 | **Kraken, Coinbase, FalconX**, "cold-storage arrangements" | HSM/cold custodians | 10% (0–35%), low |
| GameSquare (GAME) | 15,080 (2026-06-30) [SEC] | Unknown | Unnamed "regulated custodians" | Unknown | Unknown |
| Forum Markets (ex-ETHZilla) | 12,441 (2026-06-30) [SEC], all pledged to lender Equities First | 0 (liquid staking closed) | Formerly Coinbase | Lender-held | Unknown (immaterial) |
| Yueda Digital (YDKG) | ~19,929 [2ND] | Unknown | Self-custody, "do not currently engage third-party custodians" [SEC 6-K] | Unknown | Unknown |
| Parataxis Ethereum (KOSDAQ) | ~11,730 [2ND] | Unknown | Not an SEC filer, not researched | Unknown | Unknown |
| FG Nexus (now FG Communities) | **0**: sold all ETH before 2026-06-30 [SEC] | n/a | n/a | n/a | n/a |
| "Centaurus" | Not found as an ETH holder on any tracker or in EDGAR | | | | |

Notes on the entity list:
- strategicethreserve.xyz is "winding down" and lists only BitMine, so the >10k-ETH entity list comes from bitcointreasuries.net/ethereum [2ND].
- Coinbase, Bullish and Galaxy are excluded here as exchanges or brokers. Galaxy's balance-sheet ETH appears in §5.

### 1.2 BitMine: evidence

- **Holdings and staking** [SEC 8-K Ex. 99.1, 2026-10-26], https://www.sec.gov/Archives/edgar/data/1829311/000149315226048429/ex99-1.htm:
  > "As of October 25, 2026 at 2:00pm ET, the Company's crypto holdings are comprised of 6,051,933 ETH at $2,356 per ETH ... Bitmine's ETH holdings are 4.95% of the ETH supply (of 122.2 million ETH)." / "Bitmine total staked ETH stands at 5,227,037" / "assuming Bitmine's ETH is fully staked by MAVAN and its staking partners"
- **Custody language** [SEC 424B5, 2026-06-05], https://www.sec.gov/Archives/edgar/data/1829311/000149315226027521/form424b5.htm:
  > "We hold our ETH with regulated custodians that have duties to safeguard our private keys, and use multisignature keys to prevent unauthorized access in accordance with our treasury operations. Our custodial services contracts do not restrict our ability to reallocate our ETH among our custodians, and our ETH holdings may be concentrated with a single custodian from time to time."
  > "We rely on third-party custodians and validator service providers to safeguard our ETH and operate our validator nodes."
- **10-K FY2025** [SEC, 2025-11-21], https://www.sec.gov/Archives/edgar/data/1829311/000149315225024679/form10-k.htm:
  > "Our ETH treasury may be held with one or more qualified custodians or, where appropriate, in self-custody arrangements with multi-signature and other controls." / "For digital asset-related operations, we emphasize multi-party key controls, segregation of duties..." / "The Company holds its BTC in an account at Bitgo Trust ... The Company also has an account with Gemini Trust Company, LLC ... as a backup facility."

  Note: "multi-party key controls" is ambiguous. It could describe MPC or quorum approvals.
- **MAVAN** [SEC 10-Q, 2026-07-14], https://www.sec.gov/Archives/edgar/data/1829311/000162828026048157/bmnr-20260531.htm:
  > "Pier Two provides non-custodial staking infrastructure, validator operations, staking-as-a-service"
  - The Ethereum Tower management agreement was terminated on 2026-09-04 and replaced by an advisory agreement with American Validator LLC at 1.5% of rewards. Source: 8-K, 2026-09-08.
  - The MSA (Ex. 10.3, 8-K 2026-03-30) defines "'Custodian' means any third-party custodian engaged to hold, manage, and facilitate the staking of Bitmine ETH". The custodian identity is not filed. https://www.sec.gov/Archives/edgar/data/1829311/000149315226013609/ex10-3.htm
- **Former CFO separation agreement** (Ex. 10.1, 8-K 2025-12-15) lists transition tasks: "Approver on custody accounts" and "re-configuration of quorum settings with help from ETH Tower". This is a quorum-approval custody platform, not identified. https://www.sec.gov/Archives/edgar/data/1829311/000149315225027660/ex10-1.htm
- **EDGAR full-text search** within BitMine's CIK returned 0 hits for Anchorage, Fireblocks, Coinbase Custody, Komainu and Zodia. "BitGo" hits concern BTC custody and OTC desks only.
- The **FY2026 10-K** (fiscal year ended 2026-08-31) had not been filed as of 2026-10-29. It should be re-checked when it lands.
- **On-chain** [2ND label + OWN check]:
  - Arkham (2025-08-18) labels `0x8dBf95DAa0710Ee70127C8099d10Ca68132206D4` a suspected BitMine wallet. https://info.arkm.com/research/bitmine-is-the-second-biggest-crypto-treasury-company
  - Its bytecode is an EIP-1167 clone of BitGo `WalletSimple` (`0xe5DcdC13B628c2df813DB1080367E929c1507Ca0`), created by the BitGo WalletFactory. Outflows use `sendMultiSig`.
  - It received 2× 14,232 ETH from FalconX on 2025-08-15.
  - In the beacon state it is the **withdrawal address of 14 0x02 validators (27,730 ETH)** and also receives MEV/fee-recipient payments.
- **Census inference** [OWN/I]:
  - 0x02 validators holding more than 1,500 ETH (consolidated validators, the MAVAN pattern) total 15.06M ETH. By withdrawal address:

    | Withdrawal address class | ETH |
    |---|---|
    | Plain EOAs (excluding Binance and OKX) | 6.42M |
    | Lido | 2.67M |
    | Outside top 400 | 1.95M |
    | Binance | 1.10M |
    | EigenPods | 0.96M |
    | 7702 EOAs | 0.78M |
    | **BitGo WalletSimple** | **0.52M** |
    | Safe | 0.26M |
    | OKX | 0.24M |

  - So at most ~0.5M of BitMine's 5.23M staked sits behind BitGo contract multisigs. **The rest most likely withdraws to EOAs.**
  - Large unattributed 0x02 EOAs that fit a big treasury include `0x5ed5690c…` (139k), `0x08eee92b…` (121k), `0xd11d7d2c…` (117k), `0xa48c30a3…`, `0x1c5e29b1…`, `0x8ee57a09…`, `0xc1e04b6d…` and `0xd007058e…` (~100–112k each).
  - Also unattributed: `0x7e2a2fa2…` (646k, 0x01), `0x08ec37e2…` (293k) and `0xd78941…` (233k).
- **Fireblocks** [CO, 2026-06-11], https://www.fireblocks.com/blog/institutional-eth-staking:
  > "Blockdaemon, P2P.org, and MAVAN are now available via ETH Link." / "MAVAN is a Bitmine Immersion Technologies, Inc company."

  This shows that Fireblocks *clients* can stake through MAVAN. It is not evidence that BitMine's own keys are in Fireblocks.
- [2ND] Arkham (2026-09-29): 5.9M ETH, of which 5.1M staked; "a large proportion of their holdings are not visible in their Arkham entity". https://info.arkm.com/research/who-owns-the-most-ethereum-top-eth-holders-2025
- [2ND] CoinDesk (2026-03-10): BitMine moved ~9,600 ETH to Coinbase Prime.

**How to resolve the BitMine question.**
1. Cluster the large 0x02 EOA withdrawal addresses by deposit-transaction senders and funding paths (FalconX, Kraken, BitGo, Coinbase Prime). This needs Dune or Allium.
2. Read the FY2026 10-K when filed.
3. Check whether these EOAs show BitGo-TSS patterns (BitGo forwarder or fee-address funding) or Fireblocks gas-station funding.

### 1.3 SharpLink: evidence

- [SEC 10-Q, 2026-08-07] https://www.sec.gov/Archives/edgar/data/1981535/000149315226036620/form10-q.htm:
  > "As of August 3, 2026, we held approximately 888,938 in total ETH holdings, comprised of 634,255 in native ETH, 181,748 in ETH as if redeemed from LsETH and 72,935 in ETH as if redeemed from weETH"
  > "Our digital assets, including ETH and weETH, are held in our name by Anchorage Digital Bank N.A., our qualified custodian, on both Ethereum and Linea."
  > "The Company's custodial arrangements with Anchorage Digital Bank N.A. and Coinbase Inc. include operational controls designed to mitigate risks of loss, including multi-user approval quorums..."
- [SEC 10-K FY2025, 2026-03-09] https://www.sec.gov/Archives/edgar/data/1981535/000149315226009214/form10-k.htm:
  > "In native staking, ETH remains onchain with withdrawal credentials controlled by our custodian."

### 1.4 Bit Digital: evidence

- [SEC 10-K FY2025, 2026-03-27] https://www.sec.gov/Archives/edgar/data/1710350/000121390026035544/ea0279621-10k_bitdigit.htm:
  > "We safeguard and keep private our digital assets, including the ETH that we stake, by utilizing custodian solutions provided by Cactus Custody and Fireblocks, which requires multi-factor authentication."
- [SEC 8-K investor deck, 2026-09-09] https://www.sec.gov/Archives/edgar/data/1710350/000121390026098132/ea030473001ex99-1.htm:
  > "Total ETH Held 164,842.2 ETH/lsETH" / "Total ETH Staked 74,174 ETH/lsETH"
- [SEC 10-Q, 2026-08-13]: native staking "with Figment Inc."
  > "The withdrawal credentials associated with the staked ETH are designated to the Company's custodian"

  https://www.sec.gov/Archives/edgar/data/1710350/000121390026088709/ea0300693-10q_bitdigital.htm
- Cactus Custody's tech for these accounts is Unknown. Secondary sources describe multisig/HSM cold storage plus a TSS product.

### 1.5 Others: key quotes

- **The Ether Machine.**
  - [SEC Dynamix 10-Q, 2026-08-13]: "On April 8, 2026 the Company and the Seller entered into a Termination Agreement pursuant to which the parties agreed to terminate the Business Combination Agreement." https://www.sec.gov/Archives/edgar/data/2028699/000121390026089131/ea0301304-10q_dynamix.htm
  - [SEC 425, 2025-10-02]: "The Ether Reserve LLC ... has opened a custodian account with Coinbase Custody Trust Company, LLC". https://www.sec.gov/Archives/edgar/data/2080334/000121390025094982/ea0259905-425_ether.htm
- **BTCS.**
  - [SEC 10-Q, 2026-08-19]: "These assets are maintained under the Company's control through secure private keys and are not held by any third-party custodian." https://www.sec.gov/Archives/edgar/data/1436229/000149315226039249/form10-q.htm
  - [SEC 10-K, 2026-03-26]: "...the use of multi-signature authorization, hardware security modules, cold storage, and access control procedures." https://www.sec.gov/Archives/edgar/data/1436229/000149315226012916/form10-k.htm
- **Eightco** [SEC 10-K, 2026-04-15]: "Digital assets are custodied with institutional-grade providers, including Kraken, Coinbase, and FalconX." and "substantially all digital assets were held with a small number of U.S.-based institutional custodians under cold-storage arrangements." https://www.sec.gov/Archives/edgar/data/1892492/000149315226016664/form10-k.htm
- **GameSquare** [SEC 424B5, 2025-07-18]: "We will hold our Ethereum with regulated custodians that have duties to safeguard our private keys." https://www.sec.gov/Archives/edgar/data/1714562/000164117225020129/form424b5.htm
- **Forum Markets** [SEC 10-Q, 2026-08-14]: "As of June 30, 2026, the Company held approximately 12,441 ETH, which are pledged as collateral under a crypto-collateralized borrowing arrangement." https://www.sec.gov/Archives/edgar/data/1690080/000121390026090100/ea0301343-10q_forum.htm
- **FG Nexus** [SEC 10-Q, 2026-08-12]: "the Company sold all of its digital assets prior to June 30, 2026." https://www.sec.gov/Archives/edgar/data/1591890/000149315226037445/form10-q.htm
- **Yueda** [SEC 6-K, 2026-09-01]: "we hold our Digital Assets in self-custody and do not currently engage third-party custodians". https://www.sec.gov/Archives/edgar/data/1413745/000121390026095864/ea0303735-6k_yueda.htm

---

## 2. Staking providers and withdrawal-credential control

### 2.1 Census [OWN]

- **Data**:
  - Source: full validator set from `https://ethereum-beacon-api.publicnode.com/eth/v1/beacon/states/finalized/validators`, 2026-10-29.
  - Size: 818,772 validators, **44.24M ETH**. hildobby's Dune counter shows 43.95M deposited (data through about 2026-10-16) [2ND].
- **Credential types**: 0x01 holds about 57% of stake, 0x02 (compounding) about 42%, and 0x00 (BLS) 0.33M ETH.
- **Concentration**: 37k unique withdrawal addresses. The top 100 hold 53.6% of stake and the top 1,000 hold 83%.

Top-400 withdrawal addresses (31.4M ETH, 71% of stake), classified by bytecode:

| WC class | ETH | Notes |
|---|---|---|
| Plain EOA | 15.29M | Includes Binance `0x8e609ac8…` (3.54M), OKX `0xd5f8c864…` (440k) and `0xe839a3e9…` (184k); large unattributed EOAs |
| Lido WithdrawalVault `0xb9d7…293f` | 9.54M | Protocol contract (DAO) |
| EigenPods (846-byte beacon proxies) | 1.35M | ether.fi pods (protocol) + Kraken/Binance pods (owner = EOA) |
| EIP-7702-delegated EOAs | 1.39M | 1.157M Kraken (delegate `0x52756289…`); Coincheck Cold 2. Underlying key is still a single ECDSA key |
| Safe proxies | 0.89M | Multisig |
| BitGo WalletSimple clones | 0.58M | Contract multisig (BitMine wallet among them) |
| Other contracts | ~2.2M | e.g. Bitstamp `MultiSigWalletWithDailyLimit` `0x3262…` (186k) |
| Outside top 400 | 12.53M | Long tail: Rocket Pool minipools, StakeWise vaults, solo stakers, small institutions |

**Key point.** An EOA withdrawal address can be MPC (Fireblocks, Copper, Fordefi or BitGo-TSS vault), HSM (Anchorage, Coinbase cold), a hardware wallet or a hot key. Bytecode cannot separate them. The ceiling for "possibly MPC" withdrawal-address stake is about 20–25M ETH; the realistic share is far lower.

### 2.2 Protocol-contract withdrawal addresses (0% MPC at the WC level)

| Protocol | Staked ETH (date) | WC target | Governance | Evidence |
|---|---|---|---|---|
| Lido | 9.54M (2026-10-29, beacon) | WithdrawalVault proxy `0xb9d7934878b5fb9610b3fe8a5e441e8fad7e293f` | Lido DAO / Dual Governance | "Its address corresponds to the Lido withdrawal credentials (both `0x01` and `0x02` types)." https://docs.lido.fi/contracts/withdrawal-vault |
| ether.fi | 1.75M (hildobby) | EigenPods owned by EtherFiNode contracts | Multisig + timelock [2ND] | EigenLayer docs: pod address = validator WC |
| Rocket Pool | 0.41M | Minipool / megapool contracts | pDAO/oDAO | Smartnode docs [2ND] |
| StakeWise V3 | 0.30M | Vault contracts | Vault admins | Spellbook model |
| Liquid Collective (LsETH) | 0.27M | Withdraw contract | Protocol administrators | "All Liquid Collective validator keys have their withdrawal credentials set to the address of the Withdraw contract." https://docs.liquidcollective.io/eth/overview/architecture |
| Mantle (mETH) | 0.19M | Protocol contract (exact target unverified) | Mantle governance | 2ND |
| Swell | ~10–20k | Protocol contracts | Multisig | 2ND |

Additional notes:
- Lido V3 stVaults are contracts used as withdrawal addresses, but their owners can be any address, including MPC vaults. stVault TVL is Unknown.
- Lido and Rocket Pool node operators hold only BLS keys and cannot move principal, so they are irrelevant here.

### 2.3 Exchange-controlled withdrawal addresses (key tech: defer to the exchange agent)

| Exchange | Staked ETH | WC type | Source |
|---|---|---|---|
| Binance (incl. WBETH) | 3.61M (3.59M on EOAs) | EOA `0x8e609ac8…` | DefiLlama Binance adapter `withdrawalAddresses` (local copy `data/labels/raw/defillama_adapters/projects/binance/index.js`, line 71) [2ND curation] |
| Coinbase (retail + Prime/Custody incl. ETFs + cbETH) | ~4.7M (10.9% at 2026-06-30) | Not identified on-chain | Lido H1-2026 report via cryptonews [2ND]: "The same report lists Bitmine at 11.5%, Coinbase at 10.9% and Binance at 7.9% at June 30." |
| Kraken | 1.777M | 1.157M 7702 EOAs + 0.336M EOAs + 0.284M EigenPods | Dune Spellbook WC labels |
| OKX | ~694k | EOAs `0xd5f8c864…`, `0xe839a3e9…` | OKX PoR CSV 2026-10-03 (local copy `data/labels/raw/por_okx/history/por_csv_2026100300_V4_ETHnetwork.csv`) [exchange primary] |
| Upbit | 645k | Not identified | hildobby [2ND] |

### 2.4 Non-custodial providers (withdrawal address set by the client)

| Provider | Staked ETH (hildobby ~2026-10-16) | Typical client custody | MPC share best (low–high) |
|---|---|---|---|
| Figment | 1.316M (self-reported 6.26% ≈ 2.7M, Q2 2026 [CO/2ND], likely includes validators run for custodians and ETFs) | Fireblocks, Fireblocks Trust, Copper, Coinbase Custody (ETFs), Anchorage, BitGo, Ledger Enterprise, Finoa | 30% (15–55) |
| Blockdaemon | 1.086M | Exchanges and custodians; own Builder Vault MPC; Fireblocks ETH Link (2026) | 35% (10–60) |
| Kiln | 829k (Kiln Onchain "480K+" [MKT]) | Fireblocks, BitGo, Anchorage, Copper, Hex Trust, Fordefi; Ledger Live retail | 35% (15–60) |
| Everstake | 806k | Retail wallets + custodians (Copper) | 20% (5–45) |
| Bitcoin Suisse | 416k | Mostly Bitcoin Suisse custody; some client WCs | 15% (0–50) |
| P2P.org | 348k | Copper, Fireblocks ETH Link | 35% (15–60) |
| stakefish | 286k | Retail | 10% (3–30) |
| Chorus One | Unknown (<~110k) | Institutional | 30% (5–55) |
| Allnodes | Unknown | Retail/SMB | 10% (2–30) |
| Twinstake | Unknown | Institution-only | 40% (10–70) |

Evidence:
- **Figment** Fireblocks guide [CO]: "Before staking, whitelist these official Ethereum contracts in your Fireblocks workspace:" It lists the deposit contract and the EIP-7002 withdrawal-request contract `0x00000961Ef480Eb55e80D19ad83579A64c007002`. https://docs.figment.io/docs/fireblocks
  - [I] Only the withdrawal address can trigger exits through EIP-7002, so the Fireblocks vault is the withdrawal address.
- **Kiln** [MKT]: "You hold withdrawal credentials. Assets never leave your control." and "Works with Fireblocks, BitGo, Anchorage, Copper, Hex Trust, Fordefi." https://kiln.fi/validators
- **Kiln Onchain**, Consensys Diligence audit (2023-08): "WithdrawCredentials … linked to a deterministic address generated using the create2 method. This address is indirectly controlled by the EndUser, acting as the 'withdrawer.'" https://diligence.consensys.io/audits/2023/08/kilnfi-staking-consensys
- **Coinbase CDP** dedicated ETH staking [CO]: "You can stake to either pre-Pectra (0x01) or post-Pectra (0x02) validators by selecting the appropriate withdrawal credential type." https://docs.cdp.coinbase.com/staking/staking-api/protocols/dedicated-eth/usage.md

### 2.5 Fireblocks and Copper staking statistics

- **Fireblocks** [CO, 2026-06-11], https://www.fireblocks.com/blog/institutional-eth-staking:
  > "ETH staking volume on our platform has more than doubled in the last six months." / "Blockdaemon, P2P.org, and MAVAN are now available via ETH Link." / "Legacy validators remain available with Figment and Kiln." / "All three new providers, Blockdaemon, P2P.org, and MAVAN, support compounding validators only."

  **No absolute ETH-staked figure and no share of institutional staking was found.**
- **Copper**: partnership announcements only (Lido stETH, Figment, P2P.org, Everstake, mETH custody). No volumes.
- **Dune/hildobby**: no Fireblocks depositor label exists. The only Copper label (`0x7ef5d450…`) carries negligible stake.
- **Sizing [I]**:
  - Lido's H1-2026 report puts the institutional segment at 35.3% of stake.
  - Removing Coinbase/ETF custody (~11–14%) and BitMine (11.5%) leaves ~10–13% (4.5–5.5M ETH) of "other institutional" stake.
  - If 35–55% of that sits in MPC vaults, the result is ~1.6–3.0M ETH. Best guess 2.5M; range 1.0–4.5M.

---

## 3. Retail and embedded wallets

| Entity | Tech class (current) | Scale | ETH in MPC (est.) | MPC share | Conf. |
|---|---|---|---|---|---|
| **Zengo** (eToro acquisition agreed 2026-04-15) | **MPC-TSS 2-of-2** | ">2 million" users (Apr 2026) [CO] | ~30k (5k–150k) [I] | 100% | tech high / ETH low |
| **Binance Wallet (keyless)** | **MPC-TSS 2-of-3** | Not disclosed | Unknown; OoM 10k–500k | 90% (70–100) | ETH very low |
| OKX Wallet | Legacy MPC **sunset ~Nov 2025**; now seed EOA or passkey/TEE "CeDeFi" | n/a | ~0 | 0–2% | medium |
| Bitget Wallet | Seed EOA; optional 2-of-3 MPC (2023); **TEE** social login (Dec 2025) | 100M users [CO] | small | 2% (0–10) | low |
| Trust Wallet | Seed EOA; **SWIFT = passkey smart account** | n/a | 0 | 0% | high |
| Coinbase CDP Server Wallet v2 / Embedded | **TEE (AWS Nitro)**; v1 MPC wallet deprecated 2026-02-02 | Unknown | 0 | 0% | high |
| MetaMask Embedded (ex-Web3Auth) | **SSS with reconstruction** (default tiers); MPC Core Kit TSS only on Enterprise | ~50M end users (Jun 2025) [CO] | small | 5% (0–20) | medium |
| Privy (Stripe) | **SSS + TEE**, NOT MPC (verified) | >110M wallets (Mar 2026) [2ND] | 0 | 0% | high |
| Turnkey | **TEE**, NOT MPC (verified) | >50M wallets (Jun 2025) [CO] | 0 | 0% | high |
| Magic | Shards recombined in TEE + AWS KMS, NOT MPC | 50M+ wallets [CO] | 0 | 0% | high |
| Dynamic (Fireblocks, Oct 2025) | Mixed: legacy TEE + new 2-of-2 TSS-MPC (DKLs19) | "50M+ onchain accounts" (mostly connected wallets) | small | 40% (10–80) | low |
| Para (ex-Capsule) | MPC-TSS 2-of-2 (DKLS19) | "15M+ users" [CO] | small | 100% | tech high |
| Particle Network | MPC-TSS 2-of-2 (server share in TEE) | 17–30M "activations" [CO] | small | 100% | tech high |
| Lit Protocol | Threshold MPC in TEEs → **v3 Chipotle single-TEE (not MPC)** | "$400m+ secured" all chains (Oct 2025) [CO] | small, declining | 60% (20–100) | low |
| Silence Laboratories | MPC-TSS library (DKLs23); customers BitGo, Zengo, MetaMask Snap | n/a | count under customers | n/a | — |

Key quotes:
- **Zengo**: "we've replaced the traditional private key with two independently created mathematical secret shares. One share is stored on your mobile device, and the other is on the Zengo server." https://intercom.help/zengo/en/articles/2603678-our-security-model (2024-05-23)
  - eToro press release: "trusted by over 2 million individuals and businesses". https://www.etoro.com/news-and-analysis/press-releases/etoro-acquires-zengo-to-expand-self-custodial-crypto-capabilities/ (2026-04-15)
- **Binance**: "Built on the same MPC Keyless technology as Binance Wallet." / "Your private key is never fully reconstructed on any single device or server." https://developers.binance.com/docs/agentic-wallet/welcome
- **Privy**: "Every wallet uses Shamir secret sharing to produce split, encrypted key shares." / "Reconstruction happens in-memory just long enough to execute the requested action." https://docs.privy.io/security/wallet-infrastructure/secure-enclaves
- **Turnkey**: "By building on AWS Nitro Enclaves, Turnkey delivers wallet infrastructure that ensures no raw private keys…" / "TEEs offer several advantages over alternatives like Multi-Party Computation (MPC), including lower latency" https://www.turnkey.com/blog/secure-enclaves-vs-other-tees (2025-07-03)
- **Coinbase CDP v2**: "The TEE runs on AWS Nitro Enclaves" / "Private keys are encrypted/decrypted inside the enclave and never leave the enclave in plaintext." https://docs.cdp.coinbase.com/wallets/security-and-policies/security-overview
  - CDP docs [search excerpt]: "Server Wallet v1 (formerly known as Wallet API and MPC Wallet) is being deprecated as of Feb 2, 2026".
- **Magic**: "shards are retrieved and securely recombined inside the TEE, never leaving hardware isolation." https://docs.magic.link/home/security
- **MetaMask Embedded**: infrastructure docs list Embedded Wallet SDKs as "SSS (key reconstruction)" and MPC Core Kit as "TSS/MPC (no key reconstruction)". https://docs.metamask.io/embedded-wallets/infrastructure/
- **Dynamic**: "uses a default 2-of-2 threshold signature scheme" / "The complete private key never exists, even within the TEE." https://www.dynamic.xyz/docs/overview/wallets/embedded-wallets/mpc/architecture.md
- **Para**: "a 2-of-2 Multi-Party Computation (MPC) system … DKLS19 … without ever reconstructing the full private key". https://docs.getpara.com/v3/concepts/key-management
- **Particle**: "Particle uses a 2/2 TSS model." / "The two shares are never combined, not even during signing." https://developers.particle.network/social-logins/mpc-tss.md
- **Lit v3**: "Each request runs inside one TEE enclave rather than coordinating across multiple nodes." https://spark.litprotocol.com/introducing-lit-protocol-v3-chipotle/ (2026-02-26)
- **OKX sunset** [2ND]: the CEO said OKX would "completely decommission the legacy MPC wallet and launch... next-generation no-private-key wallet—CeDeFi Wallet". https://www.chaincatcher.com/en/article/2220609 (~2025-11-15)
- **Bitget** [CO PR via The Block]: "architecture uses AWS Nitro Enclaves to isolate key material end-to-end … unlike MPC wallets". https://www.theblock.co/post/381220/ (2025-12-04)

**Retail and embedded total**: ~16k–720k ETH, best ~100–200k (≈0.1–0.2% of supply). Low confidence; Binance Wallet is the main unknown.

---

## 4. Vendor aggregate disclosures (top-down cross-check)

| Vendor | Key tech | Latest aggregate figure | Date | Kind | ETH-specific? |
|---|---|---|---|---|---|
| **Fireblocks** | MPC-CMP | **$45B "assets under custody on the platform"** | 2022-01-27 | AUC [CO PR] | No |
| Fireblocks | — | **"40% Bitcoin, 30% Ether and the rest mainly tokenized assets"** | Mix as of **March 2021**, reported 2021-07-27 | Asset mix [2ND, Ledger Insights] | **Yes, 30%** |
| Fireblocks | — | ">$10 trillion" transfers secured, 2,400+ customers | Aug 2025 (job posting) [2ND] | Transfer volume, not a balance | No |
| Copper | MPC | "$10b assets secured" (homepage, undated); "$15B AUC, 400+ clients" (TOKEN2049 listing, undated) | Undated; in a sale process since May 2026 [2ND] | Marketing | No |
| Cobo | HSM/SGX custodial + MPC-TSS (in TEEs) + Safe wallets | "billions in assets" (no figure); third-party templates claim $7–18B (unreliable) | 2026 | Marketing | No |
| Dfns | MPC-TSS (CGGMP21) | "$100B+ client assets" (secondary, implausible); earlier own pages $10B/$20B "assets secured"; >10M wallets | 2024–26 | Marketing/2ND | No |
| Fordefi (Paxos, Nov 2025) | 2-party MPC | ~300 institutions; ">$120B monthly transaction volume" | Nov 2025 [2ND] | Volume | No |
| Utila | 2-party MPC | ">$8B monthly volume", ">$35B secured transactions" (Mar 2025); ">$110B cumulative" (2025 review); "over $30B monthly" (Oct 2026, 2ND) | 2025–26 | Volume | No |
| Ceffu | MPC cold wallets | 2025: "+50% Growth in Deposited Amount", "$60B+ in transactions processed"; no absolute AUC | 2025 EOY report | Growth/volume | No |
| Safeheron | MPC-TSS + SGX | "$1.5B+ peak AUC" | Undated | Marketing | No |
| Liminal | MPC + multisig | "$500M+ assets under protection" | Undated | Marketing | No |

Fireblocks evidence:
- **40/30 split.** Ledger Insights, "Digital asset custody firm Fireblocks raises $310m at $2 billion valuation", **2021-07-27**. The paragraph is now paywalled; this is the archived copy. https://web.archive.org/web/20210727142135/https://www.ledgerinsights.com/digital-asset-custody-firm-fireblocks-raises-310m-at-2-billion-valuation/
  > "Today's announcement claims that more than 500 institutions use its solution to safeguard a trillion dollars of digital assets. ... We have asked for clarification as past figures have quoted amounts as storage and transfers, not just digital assets at rest. Back in March, the assets under custody were split 40% Bitcoin, 30% Ether and the rest mainly tokenized assets, particularly stablecoins but also NFTs."
  - **The absolute size for March 2021 is Unknown.** Ledger Insights' March 2021 article reports only "Fireblocks says its network secures more than $400 billion in assets", which mixes in transfers. https://www.ledgerinsights.com/bny-mellon-picks-digital-asset-custody-firm-fireblocks-which-raises-133-million/ (2021-03-18)
  - multiples.vc repeats the split, unsourced, under its Series D entry.
- **AUC** [CO PR, 2022-01-27]: "To date, Fireblocks customers have amassed $45 billion assets under custody on the platform." / "has secured the transfer of over $2 trillion in digital assets" / "serves over 800 financial institutions". https://www.prnewswire.com/news-releases/fireblocks-raises-550-million-in-series-e-funding-to-become-the-highest-valued-digital-asset-infrastructure-provider-301469630.html
- **Crude ETH implication [I]**: $45B × 30% ≈ $13.5B ≈ 5.6M ETH at ~$2.4k (late Jan 2022). This mixes a March 2021 asset mix with a January 2022 AUC, includes exchanges' Fireblocks wallets, and is 4+ years stale. Use it only as an order-of-magnitude anchor.
- **No newer Fireblocks AUC was found.** Context [2ND]:
  - Fireblocks Trust Company (NYDFS, Aug 2024) signed Galaxy, Bakkt, FalconX and Castle Island as custody clients (Ledger Insights, 2025-10-08).
  - Axios reported Visa acquisition talks of ~$2.5B (2026-10-22); Fireblocks denied them.
- **Copper** [CO, homepage]: "Our MPC technology ensures no complete private key is ever created." and "$10b assets secured" (undated). https://copper.co/en/company/about
- **Cobo** [CO]:
  - Custodial wallets: "Secured by hardware-based isolation using HSMs and Intel® SGX".
  - MPC wallets: "Distributed TSS nodes run inside Trusted Execution Environments (TEEs)". https://www.cobo.com/
  - Portal: "the full key is never materialized at any point." https://manuals.cobo.com/en/portal/mpc-wallets/introduction
- **Dfns** [CO]: "The full private key is never revealed or reconstructed at any point." https://docs.dfns.co/core-concepts/how-mpc-wallets-work
- **Fordefi** [CO]: "each private key is split between Fordefi and the customer … without the private key ever having to be reconstructed on a single device." https://docs.fordefi.com/user-guide/welcome/product-security
- **Ceffu** [CO]: 2025 EOY report: "+50% Growth in Deposited Amount", "$60B+ in transactions processed". https://www.ceffu.com/download/2025-EOY-Report.pdf
  - **Overlap warning**: Ceffu, Dfns and Fordefi serve exchanges and custodians, so their totals overlap the other agent's scope.

---

## 5. Other non-exchange holders

| Holder | ETH (date) | Key management | MPC best (low–high) | Evidence |
|---|---|---|---|---|
| **Ethereum Foundation** | >160k migrated (2025-10-22); ~102k per Arkham (Apr 2026) [2ND]; ~70k staked (2026) | **Safe multisig** (3-of-5 tested), replacing a custom multisig. Staking uses **0x02** credentials with a Dirk distributed signer (BLS); the withdrawal address type is not disclosed | 0% (0–5) | The Block PR 2025-10-22: "over 160,000 ETH worth approximately $650 million to Safe{Wallet}" ... "3-of-5 multisig configuration". EF blog 2026-02-24: "Approximately 70,000 ETH is being staked … The validators are using Type 2 (0x02) withdrawal credentials" https://blog.ethereum.org/2026/02/24/staking |
| Galaxy Digital (balance sheet) | 61,137 (2025-12-31) [SEC] | Mixed: **Fireblocks licence** (since 2021) + own GK8 (air-gapped "Impenetrable Vault" + "uMPC") + third-party custodians incl. Fireblocks Trust | 50% (20–80) | 10-K (2026-02-26): "First Amendment to the Fireblocks License Agreement…"; "Our patented uMPC technology allows for an unlimited number of co-signers" https://www.sec.gov/Archives/edgar/data/1859392/000185939226000016/glxy-20251231.htm |
| Jump Crypto / Jump Trading | Unknown (>$300M attributed [2ND]) | **Cordial Systems "Treasury"**, MPC (2-of-2 / 3-of-4) + policy consensus; Cordial grew out of Jump's internal needs | 70% (30–95) | AWS Marketplace: "Keys are always kept safe by MPC, split in "2-of-2" or "3-of-4" fashion with Cordial Systems nodes." https://aws.amazon.com/marketplace/pp/prodview-xbqazqjdueayu ; Jump named as client [2ND] |
| Wintermute | Unknown | Fireblocks per promotional awards copy [2ND/MKT, unverified] | 60% (20–90) | BeInCrypto nomination (via search excerpt): "Fireblocks' MPC-based custody technology powers wallets and transactions for … Wintermute …" |
| B2C2 | Unknown | **Fireblocks** since 2020 [CO] | 80% (40–100) | "has maintained zero operational security incidents since adopting Fireblocks in 2020" https://www.fireblocks.com/customers/b2c2 (2025-11-21) |
| GSR | Unknown | **Fireblocks** vaults + settlement [CO case study]; Copper client logo | 80% (40–100) | https://www.fireblocks.com/customers/gsr |
| FalconX | Unknown | Client custody via **Fireblocks Trust**; own stack not disclosed | 60% (20–90) | "Assets are held at Fireblocks Trust Company in segregated, bankruptcy-remote wallets" https://falconx.io/newsroom/falconx-expands-u-s-institutional-offering-with-qualified-custody-via-fireblocks-trust (2026-02-04) |
| Cumberland (DRW) | Unknown | Unknown (DRW VC invested in Fireblocks; no custody disclosure) | Unknown | — |
| US Government (USMS/DOJ) | ~17k (2026-09-29, Arkham [2ND]); 30,007 Krewson ETH moved to Coinbase Prime 2026-07-13 | USMS contract with **Coinbase Prime** for large-cap custody (2024, 5-year, $32.5M) | 10% (0–50) | Arkham 2026-07-15 and 2026-09-29; The Block 2024-07-01 |

Arkham's 2026-09-29 holder list (https://info.arkm.com/research/who-owns-the-most-ethereum-top-eth-holders-2025) [2ND] also gives:
- 91.5M ETH for the "Beacon Deposit Contract". That is cumulative deposits, not current stake; current stake is 44.2M per my census.
- Fidelity Custody 558k; Vitalik 224k; Rain Lohmus 250k (inaccessible).

---

## 6. Double counting, caveats and next steps

- **Overlaps.**
  - Bit Digital and SharpLink stake through Figment and other non-custodial providers, so their ETH partly overlaps §2.4. It is small (<0.1M MPC).
  - BitMine's staked ETH appears in both §1 and §2. It is counted only in §1.
  - LsETH and weETH receipt tokens held by treasuries are protocol stake (§2.2). Do not count the same ETH again as custodian-held.
  - Vendor aggregates (§4) include exchanges and custodians, so they are a cross-check only and must not be added.
- **Shared limitation.** On-chain, MPC EOAs are indistinguishable from HSM, hardware-wallet or hot-key EOAs. Every MPC share here for an EOA-backed balance is a judgment from documented vendor relationships.
- **Highest-value next steps.**
  1. Attribute the large unlabeled 0x02 EOA withdrawal addresses to BitMine, Coinbase or ETF custody, using Dune/Allium deposit-sender clustering and Arkham entity pages.
  2. Read BitMine's FY2026 10-K when filed.
  3. Resolve EigenPod owners (1.35M ETH).
  4. Attribute `0x7e2a2fa2…` (646k), `0x08ec37e2…` (293k) and `0xd78941…` (233k).
- **Working data**:
  - Beacon aggregate: `research/agent_notes/wc_agg.tsv`
  - Top-400 classification: `research/agent_notes/classified.tsv`
  - Detailed sub-reports in `research/agent_notes/`: `treasury_findings.md`, `staking_findings.md`, `wallets_findings.md`.