Stocks Gain At Open On Bargain HuntingAngela Moon On Wednesday May 26, 2010, 9:43 am NEW YORK (Reuters) - Wall Street opened higher on Wednesday on bargain hunting after a recent sell-off and as U.S. Treasury Timothy Geithner flew to Europe to press for united action to tackle the region's deepening debt crisis. The Dow Jones industrial average (DJI:^DJI - News) was up 78.90 points, or 0.79 percent, at 10,122.65. The Standard & Poor's 500 Index (^SPX - News) gained 10.79 points, or 1 percent, at 1,084.82. The Nasdaq Composite Index (Nasdaq:^IXIC - News) rose 28.73 points, or 1.30 percent,...