NEW YORK (AP) — The U.S. stock market opened with small gains on Monday, keeping major indexes at record levels. Renewed confidence that stimulus measures from global central banks will help spur economic growth is supporting demand for stocks. Sentiment was supported in European markets by a rise in the closely watched Ifo business confidence survey, the first after six months of declines. Traders are also watching a meeting in Vienna on Thursday of the Organization of Petroleum Exporting Countries for a possible agreement to cut production to shore up prices.