The US stock market has witnessed its share of turbulence in recent months, but the jump in price volatility hasn't dented the leadership role of the health care sector. At the opposite extreme: energy companies continue to dominate the field in the category of downside momentum.

Based on a set ETF proxies, the Health Care Select Sector SPDR (XLV) remains firmly ahead of the pack with a 27.8% total return for the trailing one-year period (252 trading days) through yesterday (Aug. 4). That's a world above The Energy Select Sector SPDR ETF (XLE), which has tumbled by more than 27% over the same period. As for the market overall, the SPDR S&P 500 ETF (SPY) is ahead by slightly more than 11% for the trailing one-year period.

Reviewing the trailing one-year performance histories of the sector ETFs reveals an unusually wide dispersion of results. The chart below compares the funds with indexed prices re-set to starting values of 100 as of Aug. 6, 2014. Health care's leadership remains unchallenged at the moment (black line at top of chart). Meanwhile, the carnage in energy stocks is in a class of its own (purple line at bottom).

Finally, here's a profile of momentum for the sector ETFs via current prices relative to their trailing 50- and 200-day moving averages. (Note: moving average data is calculated based on split-adjusted closing prices before dividends/distributions.) The latest numbers suggest that a leadership switch may be underway. The Consumer Discretionary SPDR ETF (XLY) is currently trading at a higher level over its 50- and 200-day moving averages relative to the equivalent profile for XLV. Is that a sign that this slice of consumer stocks—Disney, Amazon, etc.—is poised to take the pole position away from health care firms in the weeks ahead?

Here's a list of the sector ETFs cited above, with links to summary pages at Morningstar.com for additional research: