As the quarter winds down, investors can look at 13-F filings to determine what the best minds on Wall Street are planning for the coming months. The Securities and Exchange Commission (SEC) requires these filings whenever an individual investor or fund holds a significant enough stake in any given stock, so this is a regular filing for big players like Warren Buffett.However, most retail investors can relate only so much to Buffett, as his cash holdings (upwards of $250 billion) are the size of many econom ...