These 2 charts should settle one of the biggest concerns around a rate hike

Barring a major economic disaster, the Federal Reserve is set to raise its benchmark rate in December.

It would be the first increase in nine years. And for several reasons other than just how rare an event this would be, there's concern out there.

One of them surrounds the dollar's response.

In anticipation of higher rates, the dollar has surged to a 12-year high, and the US dollar index has rallied 10% this year. On Monday, the dollar index crossed 100 for the first time in eight months.

However, higher rates could mean the end of this bull run.

Some strategists are making that call because during the past six monetary policy tightening cycles, on average, the dollar has weakened in the six months after the first hike.

In their 2016 market outlook published Friday, RBC Capital Markets currency strategists note that despite this, "a closer look at each of those cycles shows that there is no such thing as a 'standard' USD reaction (Exhibit 41, right panel)."

A version of the chart on the left above is the one that has some strategists convinced that the dollar's bull run is near its end.

However, the second chart uses the individual dollar reactions since 1983 to show that although the dollar has dropped most of the time, we can't draw conclusions based on the average.

So what could hold the dollar up?

"With the rest of the world easing, the US forward curve still flatter than our forecasts, and long USD positioning off the highs, we think there is room for the USD to rally further from here," RBC's Elsa Lignos and Adam Cole wrote.