Stablecoins still need a sovereign backstop

The case that stablecoins are a private-sector solution to a private-sector problem is collapsing under official scrutiny. A new IMF working paper concludes that issuers would only deserve the name if they held a larger share of genuinely safe assets and ran businesses with more than one revenue stream. The corollary, made explicit by the Fund's Tobias Adrian, is that public backstops will remain essential. That is a long way from the industry's preferred narrative of regulated-but-autonomous money.

The intellectual centre of gravity has shifted. Where the debate two years ago was whether stablecoins should exist inside the regulatory perimeter, it is now about which prudential tools apply and how aggressively. The IMF paper, by treating issuers as maturity-transforming entities rather than payment utilities, places them squarely in the category of institutions that need lender-of-last-resort access to be credible in stress. That framing is consequential: it implies the stablecoin question is not really a crypto question but a banking question wearing different software.

The reserve quality problem

Reserve composition is the cleanest place to test the IMF's thesis. The Fund's argument that issuers should hold a higher share of safe assets is, in practice, a critique of any reserve mix dominated by short-dated Treasury bills funded with overnight redemption obligations — a maturity profile that, as the Federal Reserve speech on stablecoin design standards noted, replicates the run dynamics of a narrow bank without the matching liquidity facilities. Diversified issuer revenue matters for the same reason: a business that depends entirely on the carry of its float will cut corners on reserve quality the moment rates fall.

The parallel regulatory current reinforces the point. The Prudential Regulation Authority's consultation to modernise UK liquidity standards is explicitly built on the lessons of Silicon Valley Bank and Credit Suisse — that runs now move at the speed of a group chat, and that holding nominally liquid assets is not the same as being able to monetise them inside a week. The PRA is removing the exemption that spared sovereign bonds and level 1 assets from annual monetisation testing, and pushing firms to be operationally ready to tap central bank facilities. Stablecoin issuers, whose redemption windows are measured in minutes, face a more acute version of the same problem with none of the infrastructure.

“We've focused the changes not on increasing the amount of liquid assets banks have to hold, but instead on making sure that those assets do what they say on the tin and really are usable in the event of a run.”

— Sam Woods, PRA

The harder question, which the IMF paper raises but does not resolve, is who pays for the backstop. Extending central bank liquidity to private issuers without bank charters is politically combustible; denying it leaves the singleness of money exposed every time a major issuer wobbles. The middle path — bank-equivalent prudential standards as a precondition for any access to public liquidity, as outlined in recent Federal Reserve commentary — is the most coherent destination, and probably the one regulators converge on. For markets, the operational read is that the largest issuers will end up looking and being regulated like narrow banks within the next legislative cycle, and that the spread between regulated and offshore stablecoins will widen materially before it narrows.