Warren Buffett announced he is retiring as CEO of Berkshire Hathaway at the end of the year, with Greg Abel taking over. The interesting part is how he's positioning the portfolio before he leaves. He has been a net seller of stocks for 12 quarters in a row, selling about $184 billion total. He cut his Apple stake by 73% and Bank of America by 44%. He implies valuations are too high right now, noting the S&P 500 is trading at 22x earnings. Berkshire is sitting on a massive cash pile. It looks like he prefers paying taxes on gains now to hold cash rather than staying in overvalued stocks during a potential downturn.