NEW YORK (AP) — The stock market is losing crucial support from the Federal Reserve. Omicron is causing havoc at businesses around the world. And Russia just might be preparing to invade Ukraine. These are just some of the uncertainties leading investors to sell stocks. The S&P 500 has dropped nearly 10% from its record set on the first trading day of the year, the biggest setback for Wall Street since its collapse when the pandemic first struck. The U.S. central bank is moving away from its easy money policies and preparing to raise interest rates. That likely spells more volatility for the stock market, which had another down day on Tuesday.