Stocks may have sailed higher on the Federal Reserve's tapering announcement, but David Robin of Newedge warns that the structure of the tapering timeline means that if economic data continues to improve, the market will run into a serious problem.
"If we get a surprise piece of data, if all of a sudden in February we've got the unemployment rate at 6.6 percent and three or more consecutive 200-plus nonfarm payrolls numbers, I think all bets are off," Robin said on Thursday's "Futures Now." "I think that the Fed has opened the door to exaggerated reactions due to data dependency."
(Read more: Wits beat out speed in S&P's post-taper surge)
In its statement Wednesday, the Federal Open Market Committee said that the Fed would reduce its monthly asset purchases by $10 billion, to $75 billion.
The FOMC also made it clear that economic data will determine the pace at which that amount is cut to zero, saying that it "will closely monitor incoming information on economic and financial developments in coming months."
Asset purchases are not on a preset course, it said, "and the Committee's decisions about their pace will remain contingent on the Committee's outlook for the labor market and inflation."
(Read more: Full text of Fed statement)
To Robin, Newedge's co-head of financial futures and options, this extreme data dependency could get hairy for bonds and stocks alike, as investors probably will anticipate not only faster tapering but also a faster increase on the target for the critical federal funds rate.
Fed Chairman Ben Bernanke "put the next taper squarely on data dependency and payroll data," Robin said. "It's all well and good, as long as we don't get a surprise piece of data to the upside."
If data do come in stronger than expected, he said, "it's going to be very difficult for the market not to believe it's going to be an accelerated taper which leads to an accelerated tightening." That could mean "an extended rate reaction," potentially sending stocks sinking.
While Robin said that a 10-year yield of 3 percent to 3.25 percent "is fair" in the short term, "you can't rule out that it goes beyond 3.25 in a payroll-type reaction."