(Reuters) – Shares of Capital One Financial Corp (NYSE:COF) rose in premarket trading on Tuesday after billionaire investor Warren Buffett’s holding company disclosed it had taken a stake in the credit cards-focused bank.

The bank’s stock, which was trading up 7% at $95.37, would open at its highest in more than two weeks, if gains hold.

In its quarterly disclosure after the bell on Monday, Berkshire Hathaway (NYSE:BRKa) said it had a 9.92 million share stake in the company. The stake would be worth $954 million, based on the closing price on March 31.

As of Monday, Capital One shares had lost around 8% so far this month, as financial stocks felt the effects of First Republic Bank (OTC:FRCB)’s collapse.

Besides credit cards, the McLean, Virginia-based Capital One also has a huge auto lending and commercial banking business.

Western Alliance (NYSE:WAL) Bancorp, Comerica (NYSE:CMA) Inc and KeyCorp (NYSE:KEY) rose between 1% and 3% as investors’ focus shifted away from the troubles of the regional banking sector towards the U.S. debt ceiling debate.

But PacWest Bancorp’s rally came to a screeching halt. Shares were down nearly 2% premarket after surging about 18% on Monday.