Warren Buffett's Berkshire Hathaway (NYSE:BRK.A,NYSE:BRK.B) bought up 37 percent of global silver supply between 1997 and 2006. Silver ranged from US$4 to US$10 during that period. In fact, between July 1997 and January 1998 alone, the company bought about 129 million ounces of the metal, much of which was for under US$5. Adjusted for inflation, the company's purchases in that window cost about US$8.50 to US$11.50.