Investors An Eye On Data

Investors have been keeping a keen eye on data to see if the U.S. economy has recovered from a slow start at the beginning of the year. The Federal Reserve has said it will raise rates when it sees a sustained rebound in the economy.

A September interest rate hike is "very much in play" if the U.S. economy continues to strengthen, though the Federal Reserve could also wait until December to start tightening policy, New York Fed President William Dudley told the Financial Times in an interview.

S&P 500 e-minis ESc1 were down 22.5 points, or 1.07 percent, with 399,460 contracts traded - twice the average volume at this time of the day.

Nasdaq 100 e-minis NQc1 were down 56.25 points, or 1.26 percent, on volume of 47,304 contracts. Dow e-minis 1YMc1 were down 186 points, or 1.04 percent, with 46,328 contracts changing hands.

Sysco (SYY.N) shares rose 2 percent to $38.99 in premarket trading after the largest U.S. food distributor said it terminated its merger with privately held U.S. Foods [USFOO.UL].

Seres Therapeutics (MCRB.O) fell 10.5 percent to $46 after an 86 percent rise in its market debut on Friday.

Aratana Therapeutics (PETX.O) rose 15 percent to $15.50 after the animal health drugmaker said its experimental appetite-stimulating drug was found effective in dogs in a pivotal study.

Insurer Assured Guaranty (AGO.N) fell 19.7 percent to $22.00 on Monday after BTIG downgraded the stock on concerns over Peurto Rico's debts.