By Caroline Valetkevitch NEW YORK (Reuters) – The S&P 500 ended below 4,000 for the first time since late March 2021 and the Nasdaq dropped more than 4% on Monday in a selloff led by mega-cap growth shares as investors grew more concerned about rising interest rates. The Nasdaq closed at its lowest level since November 2020. Apple shares dropped 3.3% and were the biggest weight on the Nasdaq and the S&P 500. Microsoft Corp dropped 3.7% and Tesla Inc fell 9.1%. Investors are worried about how aggressive the Federal Reserve will need to be to tame inflation. The U.S. central bank last week hiked…