A Stock Market Indicator Rarely Seen Since 1990 Hints at a Monster Rally. Here's What Investors Should Know.

The S&P 500 (SNPINDEX: ^GSPC) is currently 14% below the record high it reached earlier this year. The decline started when President Donald Trump announced tariffs on goods from China, Canada, and Mexico in February, and the losses deepened as he added new duties on steel, aluminum, and auto imports. The S&P 500 tumbled 12% during the next five trading days as Wall Street processed the radical shift in U.S. trade policy.