This Contrarian Stock Market Signal Is Losing Predictive Power

The put-call ratio, which compares the number of contracts traded in bearish versus bullish options, is widely considered a contrarian indicator; for example, when investors load up on puts allowing them to sell the underlying stock or index, markets may be primed to rally as the ratio spikes. In other words, the ratio can be a powerful indicator of the market’s mood.

Since October, however, the gauge for options on the S&P 500 Index has proved erratic. Over this period, the S&P 500 has gained and market volatility has tumbled, yet the put-call ratio spiked multiple times, on some days even showing investor bearishness at levels unseen in data going back to 1997.