After moving sideways for several weeks, we finally saw some changes in the sentiment indicators this past week. The biggest surprise came from the AAII Sentiment Survey.

The bullish percentage came in at 27.2 percent this past week, while the bearish percentage came in at 34.3 percent. This puts the ratio at 0.79 bulls for each bear.

In the past year, the ratio has had a total of 10 weekly readings where the ratio dropped below 1.0, including last week. Three of the readings came in April 2013, right before the S&P 500 rallied 125 points.

There were three more readings below 1.0 in June, and the S&P 500 then rallied almost 150 points from its late June low.

There was another reading below 1.0 in August. The S&P 500 rallied approximately 75 points from its low to the September high.

The next two readings came at the end of January and beginning of February. From the low on Feb. 5 through the high on April 4, the S&P 500 rallied almost 160 points.

Given the pattern of having the ratio drop below 1.0 and then seeing the S&P 500 rally during the ensuing month or so, it looks like the S&P 500 could rally from now until mid-May at the very least.