The world's most famous stock-picker showed a growing appetite for equities in the third quarter — including a rare move to buy his own firm's shares. Now, October's market slide opens the door for Warren Buffett to finally make a dent in his giant pile of cash. Berkshire Hathaway's chairman poured more money into stock purchases last quarter than he has in more than four years. Buffett also spent $928 million on share buybacks during a few weeks in August, a move he's typically spurned. While the repurchases amounted to less than 1% of the company's cash, they set a new precedent. "It's really important in terms of a signaling effect," Jim Shanahan, an analyst at Edward Jones, said in a phone interview. "What they've demonstrated is a willingness to use cash to buy back the stock if it reaches a value that they believe is less than intrinsic value." Buffett, 88, has been facing a conundrum.