Last week in this space, I told you about the AAII Sentiment Survey ratio jumping by more than 1 (from 1.28 to 2.34).

Investors continued to jump to the bullish camp this past week, with the bullish percentage jumping from 49.4 percent to 52.7 percent and the bearish percentage falling from 21.1 percent to 15.1 percent, putting the ratio at 3.49.

These numbers hit a number of significant levels. First, the bearish percentage of 15.1 percent is the lowest reading since July 14, 2005. The S&P 500 peaked the following week and then in the next 11 weeks it fell 6.2 percent from the high to the low.

Secondly, having the ratio jump by more than 1 point in consecutive weeks is something that has only happened on four occasions since July 1987 when my data start.

The other four instances occurred in April 2000, November/December 1999, May 1996 and December 1992.

The most recent occurrence came after the historic plunge on April 14, 2000, when the S&P 500 lost more than 10 percent in one week. Investors jumped right back in and the ratio jumped from 1.75 to 2.83 and then from 2.83 to 4.22 in consecutive weeks.

The market fought back during the following months, but wasn't able to surpass the March high before the bear market started in August 2000.

In the other three previous instances where the sentiment survey ratio jumped by one in consecutive weeks, the market saw significant declines in the following weeks or months.