By David French (Reuters) – U.S. stocks closed higher on Monday, at the end of a volatile month for Wall Street where the tech-heavy Nasdaq narrowly avoided its worst ever start to the year and the S&P 500 recorded its weakest January performance since 2009. Valuations of growth and technology stocks have come under increasing scrutiny, as investors fretted about companies trading at lofty valuations at a time when the U.S. Federal Reserve is set to begin raising interest rates to combat inflation and withdraw its pandemic stimulus measures. In early Monday trading, the Nasdaq was on course to…