When the stock market closed, the Dow Jones industrial average had risen 0.7 percent, the broad S&P 500 index 0.5 percent, and the technology-heavy Nasdaq composite index 0.8 percent.
Trading remained in positive territory throughout the day, but gains varied.
North Sea oil traded at $102.90 a barrel after falling 1.6 percent during the day.
Also on Wednesday, hard-to-assess information continued to come from the White House and Iran about possible progress and setbacks in negotiations over the Iran war.
Winners on Wednesday were chip giant AMD and processor manufacturer Intel, which rose 7.3 percent and 7.1 percent, respectively.
