Billionaire Warren Buffett Sold 39% of Berkshire's Stake in Bank of America and Is Piling Into an Industry Leader That's Gained Almost 48,000% Since Its IPO

For some investors, no quarterly event holds more significance than earnings season -- the six-week period where a majority of the stock market's most-influential businesses unveil their operating results. But a strong argument can be made that Form 13F-filing season is just as important.