News20 June, 20263 min read

Analysts flag contagion risk as MainStreet's MSUSD crypto crashes 87%

MSUSD crypto, a dollar-pegged token meant to stay near $1, plunged after verification provider Accountable said MainStreet failed to meet its standards.

MainStreet, a DeFi yield protocol behind the synthetic MSUSD stablecoin, saw its token collapse after losing Accountable, the proof-of-solvency partner whose feed markets used to check backing data.

In a June 20 post on X, Accountable said it ended its agreement with MainStreet effective immediately because MainStreet "was unable to meet our verification standards."

"We recognize that markets relied on this feed and are working closely with partners across the ecosystem as the situation evolves. We will continue to hold this standard without exception."

Accountable

The post didn't explain which standards MainStreet failed or whether the issue involved assets, liabilities, reporting, timing or another requirement.

Chart showing MainStreet MSUSD stablecoin's plunge. Source: CoinGecko

MSUSD's crash may now be spreading beyond MainStreet's own dollar token, analysts warn.

Blockchain forensic firm PeckShield warned in an X post that MainStreet's yield token, msY, plunged 70%, while a USDC lending vault had about $18 million exposed to a Morpho market where users borrowed USDC against msY.
PeckShield also pointed out that the market was 100% utilized, meaning available USDC was already borrowed out.
That can delay withdrawals for lenders and raise loss risk if the falling msY collateral no longer covers the borrowed USDC.

How MainStreet reacted

About seven hours after Accountable's statement, MainStreet said on X that it "remains fully backed," arguing that the shutdown of its third-party proof-of-reserves dashboard is "an infrastructure and reporting issue, not a solvency issue."

On Sunday, June 21, Accountable published another X post, saying it terminated its MainStreet agreement after the project "did not provide" a current reserve breakdown behind its reported backing figure, adding that MainStreet's public reports showed only an aggregate dollar value.

MainStreet isn't huge by DeFi standards, but it isn't tiny either. DefiLlama ranks it as the 10th-largest protocol in the basis-trading category with more than $70 million in total value locked.

Founded in 2025, MainStreet packages market-neutral options strategies into msUSD, a synthetic dollar token meant to be redeemable 1:1 for USDC.
The project built its early profile in Sonic's DeFi yield scene, with a Summer.fi forum proposal describing MainStreet Finance as backed by Sonic Labs.

Update June 21, 12:19 p.m. Added X statement from MainStreet

DeFi

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