BlackRock BUIDL, explained for advisors

The short answer

BUIDL is a share of BlackRock USD Institutional Digital Liquidity Fund Ltd., a private fund incorporated in the British Virgin Islands in 2023.¹ The fund holds cash, U.S. Treasury bills, and repurchase agreements, and seeks to keep each token at $1.00.² It is offered under exemptions that limit it to qualified purchasers: for an individual, $5 million or more in investments.³ Securitize, the fund’s transfer agent, runs the token contracts, and those contracts can freeze, seize, and burn a holder’s tokens.⁴

Most advisory clients do not meet the test. A client who does can hold the token only in a wallet Securitize has approved. The record, contract by contract and key by key, is the Ketju eligibility file for BUIDL. Ketju’s verdict and the events that would reopen it are in the BUIDL memo.

What does the holder own?

Each token is one share of the fund. Securitize’s August 2026 prospectus says each tokenized BUIDL share represents an ownership interest in the fund.⁴ The holder does not own any particular Treasury bill. BlackRock Financial Management manages the portfolio, and the Bank of New York Mellon is custodian and administrator.²

Income arrives as more tokens, not a higher price. Dividends accrue daily and are paid “directly to investors’ wallets as new tokens each month.”² The $1.00 is a target. The launch release warns that “BUIDL may not be able to maintain a stable value of $1.00 per token at all times.”²

There are two classes on chain. BUIDL itself was on seven networks by March 2025: Aptos, Arbitrum, Avalanche, Ethereum, Optimism, Polygon, and Solana.⁵ An I Class, BUIDL-I, sits on Ethereum only. No BlackRock or Securitize document Ketju read states the I Class minimum, fee, or who it is for.⁶ Securitize says its transaction volume rose from $2.2 billion to $5.3 billion in the quarter ended June 30, 2026, “primarily driven by subscription and redemption activity in BUIDL and BUIDL-I.”⁷

Who may hold it?

Investor status. The fund’s Form D claims two exemptions: Rule 506(c) under the Securities Act and Section 3(c)(7) of the Investment Company Act.¹ Rule 506(c) lets an issuer advertise, but only if “all purchasers in the offering are accredited investors” and the issuer “takes reasonable steps to verify” that status.⁸ Section 3(c)(7) is the higher bar. It covers a fund whose securities “are owned exclusively by persons who, at the time of acquisition of such securities, are qualified purchasers.”⁹

A qualified purchaser is a person who owns “not less than $5,000,000 in investments,” in the words of the Investment Company Act; a company investing for itself or for other qualified purchasers needs $25 million.³ SEC Rule 2a51-1 says what counts: securities, cash held for investment, and real estate held for investment. A home the client lives in does not count, and any debt taken on to buy the investments is subtracted.¹⁰ The accredited-investor bar is lower: $1 million of net worth not counting the primary residence, or income over $200,000 ($300,000 with a spouse or partner) in each of the last two years.¹¹

For a typical advisory client the answer is no. A client with $3 million in brokerage accounts and a paid-off $2 million house is an accredited investor and not a qualified purchaser: the house does not count, and $3 million is short of $5 million. That client cannot subscribe to BUIDL. Nor can the client take it from another holder, because the token moves only to wallets Securitize has approved.

The minimum. BlackRock’s March 2024 launch release set a $5 million initial minimum.² Every Form D on EDGAR, most recently an amendment signed July 23, 2026, states $100,000 for any outside investor.¹ No document Ketju read says which applies today, so the Ketju file records the higher figure until one does. That amendment also reports $5.14 billion of shares sold since the first sale on March 4, 2024, to 28 investors.¹

The account. Transfers go only “to other pre-approved investors.”² Securitize named Anchorage Digital, Copper, and Fireblocks among the custodians supporting BUIDL investors in March 2025.⁵ None of the BlackRock or Securitize documents Ketju read mentions IRAs or other retirement accounts; the file records the question as unanswered.⁶

Who can freeze it, and what can that key do?

BUIDL is built on Securitize’s DS Protocol, in which every transfer passes a compliance check against Securitize’s registry of approved investors. On Ethereum one address owns the BUIDL contract, 0xe016…b09e. Ketju’s reading of September 23, 2026 found it is a single key, not a multisig, and that the same key owns the BUIDL-I contract.⁶

The verified contract code gives that owner, and the services it appoints, these powers: pause every transfer, lock one investor’s tokens, seize tokens from a wallet, burn them, issue new tokens without the compliance check, and point the contract at new code.⁶ Securitize states the purpose in its prospectus: its “smart contracts provide mechanisms to seize or burn tokens” to fix minting or allocation errors.⁴

On Solana the token uses the Token-2022 program. Its freeze power and its permanent delegate, which can move or burn tokens in any account, are both held by one program account, APm3…2kbJ. The program that enforces the transfer rules can be upgraded by one single key, 8d36…zbB6, so whoever holds that key can change the rules for every Solana holder.⁶

These powers are how a transfer agent keeps its record right. They also mean a wallet balance is not a bearer asset: the transfer agent’s side can reverse it. The chain does not show who holds each key. Ketju records what the chain shows and reads it daily, and a change to any of these keys reopens the file.

How does the holder get out?

There are two exits, and they are different transactions.

Redeem with the fund. The holder redeems through Securitize and the fund pays dollars at net asset value. Securitize’s prospectus says BUIDL tokens “can be redeemed at their net asset value which is $1 per share and are readily convertible to cash.”⁴ It names no cutoff time or settlement date, and no document Ketju read does.⁶

Sell to Circle for USDC. On April 11, 2024 Circle announced a contract that lets BUIDL holders “transfer their shares to Circle for USDC,” which it called “a near-instant, 24/7 BUIDL off-ramp.”¹² That is a sale to Circle, not a redemption by the fund, and the announcement states no size limit. Ondo, whose OUSG fund relied on it for instant redemptions, wrote in August 2024 that Circle agreed “to initially allocate 100M USDC to buy BUIDL,” while the fund itself “can take up to a full business day to fulfill a redemption request.”¹³ Ketju found no later figure for that pool. The exit can pay out only what that pool holds on the day it is used.

The fund will not list on any exchange.² Holders may send tokens to each other at any hour, but only between approved wallets.

What has gone wrong or changed

Ketju found no break in the $1.00 value, missed redemption, or token exploit in the documents it read. That finding is bounded: public releases are not audited financials or an incident log, and Ketju has not seen the offering memorandum.¹⁴

What to record in the client file

• The client’s qualified-purchaser status, the investments counted toward $5 million, and the verification the placement agent performed.
• The class (BUIDL or BUIDL-I), the chain, and the contract address the client holds.
• The wallet, who holds its key or which custodian does, and the date Securitize approved it.
• The minimum that applied at subscription, since the launch release and the Form D disagree.
• The exit the client relies on, fund redemption in dollars or the Circle contract for USDC, and when it was last used at the position’s size.
• The Ketju file’s reviewed date, so a change to the owner key, the Solana upgrade key, or the transfer agent agreement reaches the client file.