NEW YORK — Investors extended a rally through a holiday-shortened day and pushed the S&P 500 index to its third straight record high close on Wednesday. Other major indexes also closed at record highs.The rally follows a slight easing of trade tensions between the U.S. and China. Both nations have agreed to refrain from new tariffs while they open a new round of negotiations. The development relieved some pressure on the market, though the trade war still looms over global economic growth.The S&P 500 rose 22.81 points, or 0.8%, to close at 2,995.82. The third record high close in as many days also pushed the index closer to breaching the 3,000 mark.The Dow Jones Industrial Average also reached a record, gaining 179.32 points, or 0.7%, to close at 26,966.Technology stocks led the gains, helping the tech-heavy Nasdaq composite join the record-breaking club. The Nasdaq rose 61.14 points, or 0.8%, to 8,170.23.“Clearly the trade truce with China has been a catalyst for the market even though there remain uncertainties,” said Quincy Krosby, chief market strategist at Prudential Financial.Technology companies, which tend to do a lot of business with China, have been particularly sensitive to the trade war between the U.S. and China. The sector has been broadly higher this week.