FDUSD is First Digital USD, a dollar stablecoin issued from Hong Kong that at its peak climbed into the top handful of stablecoins by market cap. Launched in mid 2023, it rode Binance's zero-fee trading promotions to a multi-billion dollar valuation, survived a public solvency accusation and a depeg scare in April 2025, and has since shrunk to about $320 million as of 26 September 2026, per CoinGecko, ranking outside the top 100. The full arc, growth driven by another company's promotions, a stress test, then decline, makes FDUSD one of the most instructive stablecoins to understand, precisely because it is not a success story or a collapse, but something in between.
Here is what FDUSD is, what actually backs it, what happened in April 2025, and what its trajectory teaches about picking a stablecoin at all.
What FDUSD is
FDUSD is issued by FD121 Limited, a Hong Kong entity operating as First Digital Labs, with reserves held by First Digital Trust, a Hong Kong registered trust company. The design follows the standard playbook. Per the issuer's own published attestation reports, each token is backed one to one by reserves of cash and short-dated US Treasuries held in segregated accounts, reviewed monthly by an outside firm. The token launched in June 2023 on Ethereum and BNB Chain and later expanded to further networks.
Its growth engine was never really its own. FDUSD arrived just as Binance phased out its BUSD stablecoin, and the exchange promoted the newcomer as the replacement trading pair, including zero-fee trading against Bitcoin and other majors, per its own announcements at the time. Volume followed the fee discount, and FDUSD's market cap followed the volume into the billions. That origin matters for everything after, because a stablecoin that relies on one exchange's promotions can lose its demand the day those incentives change.
April 2025, the stress test
On 2 April 2025 Justin Sun publicly accused First Digital Trust of insolvency and misappropriation connected to a separate stablecoin it administered, and FDUSD wobbled off its peg as traders sold first and verified later, per CoinDesk's reporting. First Digital denied the allegations, called them defamatory and announced legal action, and the practical test came within days. The issuer processed tens of millions in redemptions at full dollar value while the price recovered, per Cointelegraph, which is the one test a depeg rumour cannot fake.
Two honest readings coexist. The design worked, FDUSD returned to its intended one dollar value because the issuer honoured redemptions under fire, exactly what a reserve-backed stablecoin promises. And the episode still cost the token dearly, because a stablecoin's product is confidence, and confidence that requires a stress test to confirm is confidence discounted. The market cap chart after April 2025 tells that second story.
Why it shrank anyway
FDUSD's decline from the multi-billion peak to roughly $320 million was not a run. The most visible explanation is that the demand its promotions had rented went home. Zero-fee campaigns ended or rotated to other pairs, trading balances plausibly followed whatever the venue currently subsidised, and the regulated-stablecoin field FDUSD competed in got crowded fast, USDC expanding across more venues and networks, and new NYDFS-chartered entrants like RLUSD and PYUSD arriving with distribution engines of their own, a landscape our stablecoin explainer maps.
The lesson generalises into a checklist for judging any stablecoin. Whose balance sheet backs it, and under which regulator? Whose distribution does it depend on, its own network or a partner's promotion? And has the redemption promise ever been tested at size? On the evidence above, FDUSD has a regulated trust structure and a passed redemption test, and a demand base that belonged to someone else's promotional calendar, which is why it persists as a functioning niche stablecoin rather than either a top-three asset or a cautionary tale. Our USDC vs USDT comparison applies the same three questions to the incumbents.
Should you hold FDUSD
For trading on venues where it carries fee advantages, it does that job. As a core stablecoin holding, the honest case is thin, not because the backing is suspect but because you take the same peg-and-issuer risk class as the majors while getting less liquidity depth, fewer integrations and a demonstrated dependence on one exchange's promotional calendar. High trading volume and a deep buyer pool are what let you exit at full value during stress, and the majors simply have more of both.
For holders whose actual goal is making dollars productive, the stablecoin choice matters less than the venue's terms, a point our USDC rates roundup demonstrates across the market. EarnPark pays up to 10% APY on USDC and up to 15% APY on USDT as of September 2026, published base rates for every account holding zero PARK, the token boosting rather than gating them, with the top USDT figure coming from a high-risk monthly-settlement strategy and lower-risk instant options beneath it. Those are managed-strategy rates, not stablecoin reserve yields, so the same checklist applies, read the strategy's deployment, risk level and withdrawal terms before treating the number as yours. FDUSD is not on the supported list as of September 2026, check the app's current asset list before converting, and a conversion into a supported major only makes sense after weighing the venue's conversion costs and any FDUSD-specific reason you hold the token. The wider comparison of where stablecoins earn covers the field, and you can start earning once the dollars sit in a supported coin.
FAQ
Is FDUSD safe?
Its reserves are attested monthly, held by a Hong Kong trust in cash and Treasuries, and the issuer redeemed at par through the April 2025 stress episode, which is the strongest practical evidence a stablecoin can offer. The risks that remain are the standard class, issuer and custodian solvency, monthly reserve reports checked by an outside firm rather than a full audit of the issuer, plus FDUSD-specific concentration in exchange-driven demand.
What happened to FDUSD in April 2025?
Justin Sun accused its trust company of insolvency, the token slipped off its peg as traders fled, and First Digital denied the claims, pursued legal action and processed redemptions at par while the peg recovered within days. The episode dented confidence without breaking the mechanism.
Why did FDUSD's market cap fall?
Its growth came from exchange fee promotions rather than demand it built itself. As promotions rotated and competitors multiplied, balances migrated, taking the market cap from the billions to a few hundred million without any failure of the token itself.
FDUSD vs USDT vs USDC, which should I use?
USDT for maximum liquidity, USDC for regulated depth and DeFi, FDUSD mainly where it carries venue-specific fee advantages. For core holdings, depth and diversified distribution argue for the majors, and for earning, the venue's published terms matter more than which major you pick.