Behavioral Finance Indicators

Here are the best three:

Advancing/declining Ratio
The ratio of advancing/declining stocks often indicates if movements of stock market prices are broadly based or supported only by a limited number of stocks. The broadly based movements indicate strength while limited participation may indicate potential weakness.

AAII (American Association of Individual Investors) Sentiment
When many investors become too optimistic about the outlook, the capital markets go through a correction as all these optimistic participants are already fully invested, leaving very little new money to push markets higher. Conversely, if many investors are very pessimistic, the markets will reflect it in lower prices, which can lure bargain hunters and push up the markets quickly. The AAII sentiment indicator measures how small individual investors feel about the market (i.e., bullish = optimistic, bearish = pessimistic, or neutral). Not surprisingly, when a large majority of small and usually inexperienced investors have a particular feeling about the market, the opposite usually happens.

Equity Put/Call Options Ratio
Instead of asking less sophisticated investors how they feel about the markets, we can simply observe how they invest. The equity put/call option ratio is one of the most reliable contrary indicators of the psychology of small investors. The buyers of put options think that the market will go decline, while the buyers of call options think it will go up. Hence, a high equity put/call ratio indicates there is a lot of pessimism in the market and therefore there is good potential for an upward move. The buyers of equity options are usually small retail investors looking for a quick return on their money. Hence, they tend to be reliably wrong at important market junctions (e.g., over-optimism in April 2000 and over-pessimism in October 2002).

N.B. There is no such thing as a perfect indicator and we are always striving to improve our analysis. Please let us know if you are aware of any other indicators that work well in the markets.