Looking at the Commitment of Traders reports during the weekend, one chart in particular jumped out at me — the S&P 500 big contracts.

The small speculator group saw a drastic change when they went from a net short position of 22,076 contracts to a net long position of 24,957 contracts. However, some of the change might be attributed to the fact that September contracts expired on Friday, Sept. 19.

The last time the group was net long more than 10,000 contracts was the week of July 15. That came just ahead of the big weekly loss of 2.65 percent for the week of July 28 to Aug. 1.

Back on March 25, we saw a similar spike in the small speculator positions when the group went from net short approximately 30,000 contracts to net long approximately 23,000 contracts. This too could be attributed to contract expiration.

Regardless of the reason for the spike, I couldn't help but notice that the week of April 7 to April 11, the S&P 500 lost 2.69 percent.

Finally, the last time small speculators were net long more than 25,000 contracts was the week of Jan. 14. The week of Jan. 21 to Jan. 24, the S&P 500 lost 2.63 percent.

These could all be coincidences and they could all be tied to contract expiration dates, but if the S&P 500 drops 2.6 percent next week, I for one won't be surprised.