The cheapest, with a price-earnings ratio of 6, is Louisiana- Pacific Corp. (LPX). The Nashville, Tennessee, company makes building materials and is the entry for the Materials sector of the index. It's no mystery why the stock is cheap. The Federal Reserve has trumpeted a warning to investors that it will raise interest rates this year. Rising rates are bad for housing. At 1.5 times book value (corporate net worth per share) and 0.9 times revenue, Louisiana-Pacific may be cheap enough to discount this problem.