Specialist trader Joseph Dreyer, (L), speaks with governor Patrick King, center, and NYSE managing director Rudy Mass (R) before opening a stock after the bell on the floor, July 18, 2013. Reuters / Brendan McDermid

U.S. stock market indexes on Thursday set record highs, on a nonadjusted inflation basis, as positive economic reports and upbeat corporate earnings sparked a rally while the central bank's chairman spoke in Washington.

Morgan Stanley (NYSE:MS), Verizon Communications Inc. (NYSE:VZ), International Business Machines Corp. (NYSE:IBM) and United Health Services Inc. each reported higher-than-expected second-quarter earnings before the market opened. Meanwhile, the Labor Department released its weekly jobless benefits claims on Thursday morning, which indicated that the number of initial claims fell by 24,000 claims when compared to the prior week.

Market activity was also spurred by Federal Reserve Chairman Ben Bernanke's reassurance on Wednesday before Congress that there was no concrete timetable for the Fed to scale back its bond purchase program. On Thursday, Bernanke returned to Capitol Hill to testify in front of the Senate Banking Committee and reiterated his main point in prepared remarks.

The S&P 500-stock index, which reflects the value of the 500 largest publicly traded U.S. companies, gained about 10 points by midday, trading at around 1,690 by noon ET. A week earlier, it hit 1,675. The previous intraday record was 1,687.18, set on May 22.

The Dow Jones Industrial Average, which reflects the value of 30 top industrial U.S. companies, reached 15,571 by noon, up more than 100 points above the prior day's close. A week earlier, it closed at 15,460. The previous intraday record was 15,484.26, set on July 15.

The tech-heavy Nasdaq Composite rallied at 3,617 points, 7.57 points above Wednesday's finish. It reached its all-time closing high of 5,082.62 on March 10, 2000.