U.S. stocks turned mixed in midday trading on Tuesday as investors feared a sooner-than-expected Fed rate hike. Meanwhile, U.S. home prices rose 0.9 percent in March, according to the S&P Case-Shiller Home Price Index, released on Tuesday. The index rose 0.7 percent during the prior month. Carl Icahn said he has acquired a 'large position' in pharmaceuticals giant Allergan (AGN) - Get Report . The billionaire investor also praised Allergan CEO Brent Saunders. It's unclear exactly how many shares Icahn purchased. Facebook (FB) - Get Report , Twitter (TWTR) - Get Report , Google (GOOGL) - Get Report and Microsoft (MSFT) - Get Report agreed to new European Union regulations that would force the tech giants to review and potentially remove 'the majority of' online hate speech. The companies will have 24 hours to review user's requests for hateful content to be removed from the site. TheStreet's Scott Gamm reports from Wall Street.