Summary: USG Corp. has burned Warren Buffett before -- the Oracle of Omaha ate it in 2000, after his bet on the drywall materials company went sour along with the housing market. He timed things better in 2008, using a loan to boost his position in the company, now one of the 15 biggest in his portfolio at $1 billion. USG is topping revenue projections but missing on quarterly earnings reports, which has kept shares around the breakeven mark this year and down on the last six months. But a boost in construction in 2015 could take this bet over the top for Berkshire Hathaway's portfolio.
