A "crypto-asset safeguarding obligation" is an accounting and disclosure concept that came from a specific document: SEC Staff Accounting Bulletin No. 121 (SAB 121), issued in 2022. The bulletin addressed companies-typically exchanges and custodians-that hold crypto assets on behalf of their platform users. Its central instruction was that such an entity should put the safeguarding obligation on its balance sheet, recognizing a liability measured at the fair value of the crypto-assets it was responsible for holding, together with an offsetting asset measured the same way. Understanding the model matters because, although SAB 121 was later rescinded, the questions it raised about how custody appears in financial statements remain live.

The staff grounded the requirement in the distinctive risks of crypto custody. In the bulletin's interpretive response, the staff pointed to the significant risks and uncertainties of safeguarding crypto-assets, including the risk of loss tied to holding the cryptographic key information needed to secure and transact in the asset. SAB 121 set out the safeguarding-asset side of the entry in plain terms.

"The staff also believes it would be appropriate for Entity A to recognize an asset at the same time that it recognizes the safeguarding liability, measured at initial recognition and each reporting date at the fair value of the crypto-assets held for its platform users."- SEC, Staff Accounting Bulletin No. 121, source

What the gross presentation did

The practical effect of SAB 121 was a grossed-up balance sheet. A custodian holding, say, a billion dollars of customer bitcoin would show a roughly billion-dollar safeguarding liability and a roughly billion-dollar safeguarding asset, each remeasured to fair value at every reporting date. The two figures were intended to offset, but they inflated both sides of the balance sheet by the value of customer assets the entity did not own outright in the ordinary economic sense-it held them for users. For financial institutions, that treatment also intersected with regulatory capital, because a large reported liability can carry consequences beyond the financial statements.

SAB 121 also addressed disclosure, not just recognition. The staff said it would expect the entity to provide notes to the financial statements describing the nature and amount of crypto-assets it was responsible for holding for platform users, along with a discussion of the technological, legal, and regulatory risks and uncertainties involved-risks the staff distinguished from those present in safeguarding non-crypto assets. The legal-risk discussion noted the unique characteristics of the assets, including questions about who has rights to them in an insolvency.

The three risk categories the staff named

The bulletin's rationale rested on distinguishing crypto custody from ordinary safeguarding arrangements. The staff identified three categories of risk that, in its view, set crypto apart. Technological risks arose from both the safeguarding of assets and the rapidly changing nature of crypto-assets in the market, conditions the staff said were not present with other arrangements to safeguard assets for third parties-the keys can be lost, stolen, or compromised in ways that custody of conventional assets is not. Legal risks flowed from the unique characteristics of the assets and the unsettled questions about ownership and rights, particularly in an insolvency, where it may be uncertain whether customer crypto belongs to the customer or to the estate. Regulatory risks reflected the evolving and uneven rules governing crypto custody. Those three threads-technological, legal, and regulatory-were the staff's justification for treating a safeguarding obligation as significant enough to surface on the balance sheet rather than in the notes alone.

This framing is why SAB 121's effect reached beyond accounting. By requiring a custodian to recognize a liability equal to the fair value of customer crypto, the bulletin made the size of the custody business visible in a single number, but it also drew the obligation into areas-such as regulatory capital for banks-where a reported liability carries consequences. Several banking organizations and their trade groups objected that the treatment discouraged regulated institutions from offering crypto custody at all, because grossing up the balance sheet by the value of customer assets could interact with capital and leverage requirements. That tension between investor-protection disclosure and prudential treatment was a recurring theme in the debate over the bulletin and helps explain why it became one of the more contested staff pronouncements of its era.

Why the term still appears in filings

SAB 121 did not survive. In January 2025 the SEC staff issued Staff Accounting Bulletin No. 122, which rescinded the interpretive guidance in Topic 5.FF-the codified home of SAB 121-effective January 30, 2025. Entities that had recognized a safeguarding liability and offsetting asset derecognized them on a fully retrospective basis, and the gross presentation came off the balance sheet. After the rescission, whether to recognize any liability for the risk of loss is evaluated under the general loss-contingency framework rather than the automatic fair-value gross-up SAB 121 had imposed.

So why learn a rescinded rule? Because the vocabulary persists in disclosures, the underlying obligation did not disappear-only its accounting treatment changed-and investors still need to understand what "safeguarding obligation" meant when it shaped years of crypto-platform balance sheets. Reading a 2023 or 2024 exchange or custodian filing requires knowing that the inflated, paired liability-and-asset lines reflected SAB 121's model, and that their later removal reflects SAB 122 rather than any change in the assets being held.

One caveat is worth stating. SAB 121 was staff interpretive guidance, not a rule, and the staff itself noted that its statements are not rules of the Commission. But during its life it functioned as the operative answer to how a custodied crypto obligation appeared in GAAP financial statements, and the safeguarding-obligation concept it defined is the reference point against which every subsequent change-including the move to a contingency-based model-is measured.