“The 2015 sell-off came, both markets were hit,” Gordon said of the S&P 500 and XLE in an interview with CNBC. “As the S&P eventually found its footing, it broke to new highs here but you’ll notice that the XLE also started to recover off the lows but did not come close to eclipsing the 2014 high, a major warning sign.”

XLE currently resides more than 25% below its 200-day moving average and more than 32% below its 52-week high.

For the week ended Dec. 20, investors pulled $456 million from XLE, a total surpassed by just four other ETFs.

Rivals to XLE include the Vanguard Energy ETF (NYSEArca: VDE), iShares U.S. Energy ETF (NYSEArca: IYE) and the Fidelity MSCI Energy Index ETF (NYSEArca: FENY).

For more information on the oil market, visit our energy category.