Billionaire investor Ken Griffin’s hedge fund Citadel has taken a 5.3% stake in Western Alliance Bancorp amid turbulence in the banking sector after Silicon Valley Bank’s collapse, according to a regulatory filing released Monday . Citadel bought 5,781,968 shares of Western Alliance, according to the filing. The hedge fund owns thousands of individual stocks and often trades in and out of positions quickly. However, it’s fairly rare for Citadel to take big stakes that require separate filings. A spokesperson at Citadel declined to comment. WAL 5D mountain Western Alliance Bancorp The bank stock rallied more than 40% Tuesday following a 47% sell-off on Monday. The big comeback followed regulators’ extraordinary actions to backstop all depositors in failed Silicon Valley Bank and Signature Bank and offer additional funding to other troubled institutions. On Monday, Western Alliance said it saw only “moderate” outflows , and its cash reserves exceed $25 billion. The bank had $67 billion in total assets as of the end of 2022 . “Western Alliance has taken additional steps to strengthen its liquidity position to ensure that we are in a position to meet all of our client funding needs, including increasing our borrowing capacity,” the bank said in a statement. Citadel outperformed the S & P 500 last month, continuing its strong performance. Its multi-strategy flagship Wellington fund is up 2.8% this year through February, CNBC previously reported. The hedge fund soared a whopping 38% in 2022, marking the firm’s best year ever.