Warren Buffett's company picked up nearly 36 million shares of JP Morgan Chase stock in the third quarter and eliminated its stake in Walmart as part of a number of changes in its portfolio.
Berkshire Hathaway filed a quarterly update on its stocks with the Securities and Exchange Commission on Wednesday (US time).
Buffett's Omaha, Nebraska-based company also revealed a new stake in software maker Oracle of 41.4 million shares.
Investors follow what Berkshire buys and sells closely because of Buffett's successful track record.
Berkshire officials don't generally comment on these quarterly filings, and the filings don't make clear who made all the investments.
Buffett handles the biggest investments in Berkshire's portfolio, such as Coca-Cola, Apple and Wells Fargo.
He has said that investments of less than $1 billion are likely to be the work of Berkshire's two other investment managers.
Even before the new JP Morgan stake, Buffett's company was a major investor in big banks.
During the quarter, Berkshire added to its investments in Bank of America, PNC Bank, Goldman Sachs, US Bancorp and the Bank of New York Mellon.
Berkshire trimmed its Wells Fargo investment, but it has been doing that periodically to keep its holdings under 10 per cent of the bank's stock and avoid additional restrictions.
Berkshire appeared to have sold off its 1.4 million Walmart shares during the quarter because the investment wasn't listed on Wednesday's filing.
The company added a few more Apple shares during the quarter to give it 252.5 million shares of the iPhone maker, but the purchases were modest compared to most of the past year.
At the end of last year, Buffett's company held 165.3 million Apple shares.
Buffett has said he looks at Apple like a consumer products company with a strong competitive position, rather than as a tech company.
Besides investments, Berkshire owns more than 90 companies, including insurance, retail, manufacturing, railway and candy companies.
