Bitcoin BTC$87,475.81, ether ETH$2,853.69 and other major tokens slipped early Monday, extending a bruising November close amid fresh panic from DeFi platform Yearn Finance.

BTC, the leading cryptocurrency by market value, fell over 3% to nearly $87,000 during the early Asian trading hours. Ethereum's native token ETH fell 5% while SOL, DOGE, XRP fell over 4%, according to CoinDesk data.

The sell-off accelerated hours after Yearn's X alert flagged an "incident" in the yETH liquidity pool while mentioning that its V2 and V3 Vaults remain secure and unaffected.

Social media chatter suggested that the attacker exploited a vulnerability to mint vast amounts of yETH in a single transaction, draining the liquidity pool and making off with around 1,000 ETH ($3 million), which was routed through mixers. YETH is a user-governed liquidity pool token consisting of various Ethereum Liquid Staking Derivatives (LSTs).

Yearn's issue comes days after leading Korean exchange Upbit suffered a multi-million dollar hack and underscores how institutional inflows have bloated crypto market valuations without fortifying the security infrastructure.

The early Asian session sell-off triggered liquidations exceeding $400 million in leveraged crypto futures, primarily affecting long positions, according to data source Coinglass. This indicates that many traders were betting on a price rebound and were caught off guard by the sudden downturn.

Bitcoin ended November (UTC) with a 17.5% loss, the biggest since March, even though prices recovered from nearly $80,000 to over $90,000 in the final week of the month. Ether fell 22%, registering its worst performance since February.

The dour performance came as institutional demand weakened significantly. The U.S.-listed spot BTC ETFs bled $3.48 billion in net outflows in November, the second-largest redemption on record, per data source SoSoValue. Ether ETFs lost a record $1.42 billion in outflows.

1:29 UTC: Adds commentary on liquidations, November performance and ETFs.