Caution after Wall Street caps off worst week in years.

SAN FRANCISCO (Reuters) - Signs that a long-awaited correction may have arrived on Wall Street will keep investors on edge on Monday after the S&P 500 closed off the week with its biggest percentage drop in two years.

The S&P 500 has slumped 3.89 percent since hitting a record high a week ago, trimming its gain in 2018 to 3.2 percent.

With the S&P surging more than 20 percent over the past year, selloffs like Friday's 2.12 percent drop have become rare. No session last year suffered a loss of 2 percent or more, and 2016 had only four declines of that magnitude.

"Sentiment was getting a little frothy, and we were developing some complacency in the market. Now that complacency is coming out of the market," said Keith Lerner, chief market strategist at Suntrust Advisory Services in Atlanta.

By Noel Randewich.

Full story at Yahoo News.