Stock traders’ ‘WTF indicator’ is going off. Why that is a bullish sign — at least for now.

Many investing professionals probably expected the S&P 500 would fall on Monday. Instead, the index rose by a full percentage point, finishing at its highest level in almost six weeks.

​Many investing professionals probably expected the S&P 500 would fall on Monday. Instead, the index rose by a full percentage point, finishing at its highest level in almost six weeks.