US Stocks Indexes Mixed as Oil Prices Slide<br />REITS RALLY: Several real estate investment trusts were trading higher as investors sought out stocks<br />that pay high dividend yields as bond yields headed lower.<br />U. S. stock indexes wavered between small gains and losses in morning trading Monday, giving up some of their gains from earlier in the day.<br />Investors bid up shares in utilities, real estate investment trusts and other high-yield paying stocks.