Mere coincidence or freaky Fed?

File this as one of the more bizarre things I've seen in my time studying the stock market.

While researching a segment on market returns and the Federal Reserve, I stumbled across the following:

When the Fed released the minutes of its January, 2013 meeting on Feb. 20 of last year, the S&P 500 opened at 1,530. When the central bank released the minutes of its July, 2013 meeting on Aug. 21 of last year, the S&P 500 opened at 1,650. Thus, the gain in the S&P 500 between Fed minute release dates was 7.84 percent.

Fast forward to this year.

When the Fed released the minutes of its January, 2014 meeting on Feb. 19 of this year, the S&P 500 opened at 1,838. The Fed releases its July, 2014 minutes Wednesday afternoon and the S&P 500 opened at 1,981.

Read MoreWall Street expects really dovish Fed on rate hikes

The gain between the Fed minute release dates is—wait for it—7.78 percent.

More simply, the gain in the S&P 500 between the same Fed minute release time periods the past two years is effectively exactly the same.

Cue spooky music.

Of course, data alone do not a story make, no matter how odd. The real questions here seem to be: Does this show that as long as the Federal Reserve continues to do the same thing that stocks will do the same thing? Or is it just random nonsense with no greater meaning?

My feeling is that it is more the latter. A lucky coincidence that makes a nice headline. Still though, one is hard pressed to deny it is a little odd.

If you're wondering, the "trend" ends at two years. The gains between the February to August, 2011 and February to August, 2012 Fed minute releases were minus 9 percent and plus 4.5 percent, respectively.

Source: FactSet

By CNBC's Brian Sullivan