Although Buffett is 94 years old, investors still wait on the edge of their seat for clues as to which stocks he's buying and selling. After all, mirroring his trading activity has been highly profitable for decades. Berkshire Hathaway's quarterly Form 13F filing with the Securities and Exchange Commission (SEC), along with select Form 4s, provides investors with a concise snapshot of which stocks Warren Buffett has been purchasing and selling. Based on a slew of regulatory filings, we know the Oracle of Om ...