stablecoin

Aqua (also known as AquaBot) was a Solana-based Telegram trading bot that conducted a presale in September 2025, raising approximately 21,770 SOL ($4.65 million) from retail investors before executing an apparent exit scam. On-chain investigator ZachXBT flagged the project after presale funds were split into four tranches, routed through intermediary wallets, and sent to instant exchanges hours before the scheduled token generation event. The project had secured endorsements from multiple established Solana ecosystem participants — including Meteora, Helius, Dialect, SYMMIO — and had received a near-perfect audit score from QuillAudits just days before the alleged rug pull.

Tapioca DAO is an omnichain DeFi money market built on LayerZero, offering a CDP stablecoin (USDO) and isolated lending markets (Singularity/Big Bang) across Arbitrum and BNB Chain. On October 18, 2024, the protocol suffered a critical security breach when a team member was targeted by a social engineering attack attributed to North Korea's Contagious Interview campaign, resulting in private key compromise, drainage of TAP token vesting contracts, and the minting of 5 quintillion USDO. Approximately $4.4–4.7 million was stolen before a partial counter-exploit recovered roughly 996 ETH (~$2.7 million), leaving the protocol treasury down approximately 45% and the TAP token price collapsed over 95%.

Ethena is a DeFi protocol founded in 2023 by Guy Young that issues USDe, a synthetic dollar stablecoin backed by delta-neutral perpetual futures hedges on centralized exchanges. The protocol reached $14 billion in supply at its 2025 peak before contracting sharply to approximately $5.9 billion following a flash crash in October 2025 and BaFin's enforcement action that forced Ethena GmbH to cease EU operations. Multiple concerns have been raised including: a German regulatory shutdown citing MiCA breaches and alleged unregistered securities offerings via sUSDe; insider airdrop farming allegations involving 180 million foundation-controlled ENA tokens; two separate security incidents (Discord hack July 2024 and domain registrar compromise September 2024); and structural risks tied to funding rate volatility, exchange counterparty exposure, and an undersized reserve fund relative to protocol TVL.

Circle Internet Group is the issuer of USDC, the second-largest USD-pegged stablecoin by market capitalization. Circle has faced sustained criticism from blockchain investigator ZachXBT and others for its policy of refusing to freeze USDC linked to hacks or scams without a formal court order or law enforcement mandate, which critics allege has allowed over $420 million in illicit funds to flow freely since 2022. The company went public on the NYSE in June 2025 under the ticker CRCL and received conditional OCC approval for a national trust bank charter in December 2025.