Warren Buffett's Berkshire has stepped up its efforts to sell shares of Bank of America (BAC), having dumped more than $3.8 billion in Bank of America stock since mid-July.

Berkshire sold about 19.2 million shares of Bank of America between July 30 and Aug. 1, valued at about $779 million, regulatory filings show. Since July 17, Buffett's businesses have sold 90.4 million shares of Bank of America stock. However, Berkshire remains the largest shareholder in Bank of America with 940 million shares, or about 12.1% of total shares outstanding, with a market value of about $37.2 billion.

Berkshire must continue to report its sales until its stake drops below 10 percent, which Berkshire is due to do on Saturday morning when it reports its second-quarter earnings.

Shares of Bank of America have risen about 25 percent over the past year and are trading at more than 1.2 times book value. That puts the value of Berkshire's holdings at more than $45 billion, more than triple the $14.6 billion it originally invested.

Berkshire has continued to invest in Bank of America since 2011, when it purchased $5 billion in preferred stock. The investment demonstrated Buffett's trust at the time in Bank of America CEO Brian Moynihan's ability to restore the bank's operations after the 2008 financial crisis. Buffett had said in April 2023 that he liked Moynihan a lot and said he did not want to sell the bank's stock.