Crypto-friendly bank Signature Bank (SBNY) faces a putative class-action lawsuit for its involvement in the operations of the now-failed cryptocurrency exchange FTX.

Statistica Capital, an algorithmic trading firm, and Statistica Ltd. claim the bank "had actual knowledge of and substantially facilitated the now-infamous FTX fraud," according to a filing in the U.S. District Court for the Southern District of New York dated Feb. 6. "In particular, Signature knew of and permitted the commingling of FTX customer funds within its proprietary, blockchain-based payments network, Signet."

Statistica says it advised Signature the funds were meant for FTX, but the bank allowed it to be transferred to accounts controlled by Alameda Research, the trading firm owned by FTX founder Sam Bankman-Fried.

It was the revelation of the blurry lines between FTX and its supposedly separate sister firm Alameda that brought about FTX's swift downfall, having first been exposed by CoinDesk in early November.

FTX was one of the bank’s clients, although the crypto exchange’s deposits with Signature amounted to less than 0.1% of the bank’s overall deposits. Previously regarded as one of the Wall Street's most crypto-friendly banks, it remains to be seen whether its appetite for cryptocurrency will be soured as a result of FTX's collapse.

Signature's Nasdaq-listed shares were down less than 1% in pre-market trading.

The firm did not immediately respond to CoinDesk's request for comment.

Statistica Capital is a British Virgin Islands-licensed company offering algorithmic trading focusing on automated strategies across different trading platforms, according to its website.

Read more: Binance Says Signature Bank Won’t Support Transactions for Crypto Exchange Customers of Less Than $100K