@AhGong:13F filings provide a way to get insights from the "smart money." Institutional investors of big funds may better understand the market than retail investors. As a result, they may have a bigger chance of success. By analyzing broader figures, such as industry distribution and top buys and sells, you may identify certain pack behaviors of hedge funds and get a clue about what the market is thinking. Reading 13F filings is an excellent way to learn investment strategies from great investors. Well-known managers like Warren Buffett, Charlie Munger, and Bill Ackman have their own investment philosophies and strategies. Following your gurus' 13F filings every quarter and observing how their holdings change from quarter to quarter, you may learn how they apply investment strategies in practice.