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The popular FANG basket of stocks could be out of gas after stellar returns last year — and that could be troublesome for the stock market.
FANG is an acronym created by Jim Cramer for a basket of top-performing technology stocks — Facebook, Amazon.com, Netflix and Alphabet (formerly known as Google). The S&P 500 would have been decidedly more negative for 2015 if it were not for these four stocks.
But FANG giveth and FANG taketh away.
Forget oil stocks, all four FANG stocks are down more than 3 percent this year, and that's why the market is faltering, statistics show. The bull market has lost its leader.
Using Kensho, a quantitative tool used by hedge funds, CNBC Pro looked at what the market does when FANG stocks trade down on any given trading day over the last three years.
The Kensho analysis suggests that markets are becoming more sensitive to FANG stocks on down days. Last year, the traded negative about 80 percent of the time when the basket slid.
Consequently any decline in the FANG stocks going forward may have more serious implications for the general market in 2016.
Read More Navellier: 'FANG,' ETFs among bubbles set to burst
Disclosure: NBCUniversal, parent of CNBC, is a minority investor in Kensho.