US stock indexes closed slightly higher Wednesday as gains in banks were partly outweighed by a slump in energy companies, the AP reports. Technology stocks also rose. Retailer Duluth Holdings slumped after reporting disappointing earnings. Crude oil prices fell sharply following an unexpected buildup in supplies last week. That helped send energy stocks lower, including rig operator Transocean. The Standard & Poor's 500 index rose 4 points, or 0.2%, to 2,433. The Dow Jones industrial average gained 37 points, or 0.2%, to 21,174. The Nasdaq composite increased 22 points, or 0.4%, to 6,297. (More stock market stories.)