Investing.com - Amazon (NASDAQ:AMZN) now has the second largest market capitalization among U.S. companies, thanks to a huge rally in its share price over the past 12 months.But that's not the only recent change in the top ten rankings.Here's how the market caps stack up along with the companies' 12-month price performance.Apple (NASDAQ:AAPL) is still No.1. Amazon has overtaken Alphabet (NASDAQ:GOOGL), having passed Microsoft (NASDAQ:MSFT) earlier this year. Berkshire Hathaway (NYSE:BRKa) has replaced Facebook (NASDAQ:FB) at No. 5. Facebook is now No. 6 after its recent swoon. JPMorgan Chase (NYSE:JPM) ranks seventh followed by Johnson & Johnson (NYSE:JNJ) and Bank of America (NYSE:BAC). ExxonMobil (NYSE:XOM) remains last and is the only company whose stock has declined over the past 12 months.