Monday's stock market plunge dimmed traders' outlook that the Federal Reserve will raise interest rates as much as it has indicated.

Just a few weeks after the market finally had come around to the Fed's way of thinking that three quarter-point rate hikes would be appropriate this year, the day's trading changed sentiment.

Traders on the fed funds futures market now are indicating a less than 50 percent chance that the central bank will move three times this year.

That move came on a day when the Dow industrials saw their biggest intraday drop ever — a harrowing 1,500 point plunge that came amid worries over rising interest rates.

"If this market's going to behave like that that's going to put into question three to four hikes this year," said Ilya Feygin, senior strategist at WallachBeth Capital.

March is still very much in play for an increase, with traders assigning a 71.9 percent chance that the Federal Open Market Committee will move at its next meeting, according to the CME's FedWatch tracker.

However, June is now iffy, with the prospects dipping to 50.3 percent from nearly 60 percent just a day ago. September now seems a more likely candidate for the second move, at a solid 72.9 percent.

That could be it, though, as December's chances stand at just 44.3 percent, down from 63 percent a day ago.

That puts three hikes barely in play, though continued bouts of volatility likely will put even more pressure on the Fed, which almost never surprises the market when it comes to rate increases.

"I don't think today's action or yesterday's action is going to cause the Fed to change their mind. Now if this goes on for another three or four days and we're down 500, 8000, 1,000 points maybe yes," said Kenny Polcari, director at O'Neill Securities. "The market is at these extraordinary highs because the Fed kept pumping money into the system and said everyone don't worry about it. Now we're in a position where we don't know how to get out."

—With reporting by Evelyn Cheng and Michelle Fox.