Dow tumbles over 600 points early Monday as Wall Street extends decline ahead of Fed decision, earnings wave

U.S. stock benchmarks were under pressure early Monday, falling sharply as the downtrend that has pressured stocks this year continues apace.

Investors are watching for an important two-day meeting of the Federal Reserve, the first of the year, that is set to kick off on Tuesday.

What’s happening

• The Dow Jones Industrial Average
  DJIA,
  -1.69%
  fell 688 points, or 2%, to 33,586.

• The S&P 500 index
  SPX,
  <bg-quote field="percentchange" format="0,000.00%" channel="/zigman2/quotes/210599714/realtime"…