(CNBC) U.S. stocks traded lower on Friday, the last day of trade for the month, as investors digested economic data and remained cautious on continued concerns about Greece. (Tweet This)

The Dow Jones industrial average traded about 80 points lower after falling more than 150 points to dip into negative territory for the month. The Dow transports traded about 0.70 percent lower, up from an earlier decline of more than 1 percent.

“Most of this move is keying off Greece and the rhetoric surrounding Greece,” said Jack Ablin, chief investment officer at BMO Private Bank.

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