(Corrects 3rd bullet to delete erroneous reference to CARES act, also deletes reference to CARES act in paragraph 7) * Pfizer to seek emergency green light from FDA * Chip-makers, stay-at-home stocks outperform * Mnuchin to let Fed’s lending program expire on Dec. 31 * Dow down 0.45%, S&P off 0.19%, Nasdaq up 0.17% NEW YORK, Nov 20 (Reuters) - The S&P 500 and the Dow edged lower on Friday as investors headed into the weekend grappling with disappointing fiscal stimulus news and uncertain efforts to combat a spiraling COVID-19 pandemic with vaccines. Semiconductor stocks and other stay-at-home plays, which have thrived throughout the health crisis, helped keep the Nasdaq green. Throughout the week, investors whipsawed between economically-sensitive cyclical stocks and pandemic-resistant market leaders. The S&P 500 and the Dow were on track to post marginal losses for the week, while the tech-laden Nasdaq appeared set to settle a bit higher than last Friday’s close. “There’s an ebb and flow to the market and the vaccine represents the hope,” said Matthew Keator, managing partner at the Keator Group, a wealth management firm in Lenox, Massachusetts. “The time it will take to see it distributed and take effect reflects the reality of the situation. With the rising cases of the virus and the shutdowns at the state level that’s something the market is paying close attention to.” U.S. Treasury Secretary Steven Mnuchin announced late Thursday that he would allow key pandemic-relief lending programs at the Federal Reserve to expire at the end of the year, saying the $455 billion allocated last spring under the CARES act should be returned to Congress to be reallocated as grants for small companies. The decision to pull the plug on lending programs deemed essential by the central bank comes at a time of spiraling new coronavirus infects and a fresh wave of layoffs, and was called “disappointing” by Chicago Federal Reserve president Charles Evans. Record infection numbers have caused COVID hospitalizations to soar by 50% and have prompted a new round of school and businesses closures, curfews and social distancing restrictions, hobbling the economic recovery from the deepest recession since the Great Depression. In the latest development in the race to develop a vaccine, Pfizer Inc said it would apply to the U.S. Food and Drug Administration for emergency use authorization of its COVID-19 vaccine, the first application of its kind in the battle against the disease. The Dow Jones Industrial Average fell 132.83 points, or 0.45%, to 29,350.4, the S&P 500 lost 6.66 points, or 0.19%, to 3,575.21 and the Nasdaq Composite added 20.16 points, or 0.17%, to 11,924.87. Of the 11 major sectors in the S&P 500, industrials were down the most, while utilities were enjoying the largest percentage gains. The Philadelphia SE Semiconductor index outperformed the broader market for the second straight session, rising 0.6% Stay-at-home beneficiary Zoom Video Communications Inc was up 6.8%, providing the biggest lift to the Nasdaq, while reopening play Boeing Co was the heaviest drag on the blue-chip Dow. Gilead Sciences Inc shed 0.8% as a World Health Organization panel advised against the use of the company’s COVID-19 treatment remdesivir, citing lack of evidence the drug improves survival or reduces the need for ventilation. Declining issues outnumbered advancing ones on the NYSE by a 1.08-to-1 ratio; on Nasdaq, a 1.06-to-1 ratio favored advancers. The S&P 500 posted 16 new 52-week highs and no new lows; the Nasdaq Composite recorded 112 new highs and seven new lows. (Reporting by Shivani Kumaresan and Medha Singh in Bengaluru and Stephen Culp in New York; Editing by Shounak Dasgupta and Tom Brown)