This will be key factor in future Fed decisions

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What's next for the Fed? Five truths for 2016

Don't expect the Fed to have any big surprises in 2016, no matter what current conditions might suggest.

As a history-making year comes to a close for the U.S. central bank, investors continue to try to read the tea leaves as to what to expect in the 12 months ahead.

A divergence in expectations between where the market expects rates to be and where Fed officials have placed their own estimates has convinced some that the Fed may take on a more hawkish tone.

On one hand, there was the so-called dot plot, or the diagram where Federal Open Market Committee members indicate where they think the fed funds rate will be in the years ahead. According to the chart released along with the rate hike, the FOMC expects four moves in 2016 — presumably one at each of the meetings where Chair Janet Yellen holds a news conference afterward.

On the other hand, there are market participants — namely the traders who place their own bets on when the Fed will move on the rate banks charge each other to borrow money. Futures are indicating the likelihood of just two or three increases in the year ahead, with a 60 percent chance the first will come in March.

This conflict, the thinking goes, could rattle markets that have come to depend on the Fed for a historically high level of accommodative monetary policy.

Read MoreThe Fed raised rates. So what happens now?

In some quarters, the allegedly hawkish tone of the central bank statement was even welcome news to those who think the FOMC should be more aggressive now that the Dec. 16 rate hike is behind it.