Oct 1 (Reuters) - Wall Street stocks surged to a higher close on Friday, kicking off the fourth quarter in a buying mood boosted by positive economic data, progress in the battle against COVID, and Washington developments on the potential passage of an infrastructure bill. All three major U.S. stock indexes oscillated earlier in the session, but began trending higher by late afternoon, led by economically sensitive cyclicals. The rally gained momentum after the White House announced U.S. President Joe Biden was getting more involved in negotiations over the infrastructure spending bill being debated on Capitol Hill. Even so, all three indexes ended below last Friday"s close, with the S&P 500 (.SPX) and the Nasdaq Composite (.IXIC) posting their biggest weekly percentage drops since February. "There was a broad based recovery today. Markets were not fixated today on new taxes or tapering," said David Carter, chief investment officer at Lenox Wealth Advisors in New York. "In a shift from the past few weeks there"s been no big news from Washington, so markets were forced to focus on positive economic data and a new COVID medication." Merck & Co Inc (MRK.N) revealed that a recent study showed its experimental oral drug for COVID-19 cut risk of death and hospitalization by about 50%, sending its shares jumping and boosting economic reopening sentiment. read more While Biden signed into law a stop-gap bill to keep the government running through Dec. 3, lawmakers only succeeded in kicking the can down the road. read moreThis lack of resolution prompted rating agency Fitch to warn that the United States" "AAA" credit rating could be at risk. "Markets don"t believe the debt will be downgraded or a debt ceiling deal won"t be struck but it still adds uncertainty which is always a problem for the markets," Carter added. A host of economic data released on Friday showed increased consumer spending, accelerated factory activity and elevated inflation growth, which could help nudge the U.S. Federal Reserve toward shortening its timeline for tightening its accommodative monetary policy. read more Philadelphia Fed President Patrick Harker repeated his view expressed in a speech on Wednesday that he believes the central bank should begin tapering its asset purchases "soon," but reiterated that he did not expect it to hike key interest rates until late next year or early 2023. Unofficially, the Dow Jones Industrial Average (.DJI) rose 488.73 points, or 1.44%, to 34,332.65, the S&P 500 (.SPX) gained 49.88 points, or 1.16%, to 4,357.42 and the Nasdaq Composite (.IXIC) added 108.76 points, or 0.75%, to 14,557.34. All 11 major sectors in the S&P 500 ended higher, with healthcare stocks (.SPXHC) in the back of the pack. The sector"s gains were capped by a drop in shares of COVID vaccine maker Moderna Inc (MRNA.O) in the wake of the Merck news. read more Economic optimism prompted value stocks (.IVX) to outperform growth (.IGX), and transports (.DJT) and smallcaps (.RUT) to fare better than the broader market.