With increased spending thanks to the Affordable Care Act (ACA, or Obamacare), rapid innovation thanks to biotech, and almost unbeatable momentum, XLV was a huge equity market leader for most of this bull market. Since 2014, Energy, which had kept up pretty well, melted down. Below, we chart the ratio of XLV (the S&P 500 Health Care sector ETF) and XLE (the S&P 500 Energy sector ETF). When the top chart is rising, Health Care is outperforming, and vice-versa. As shown, after years of steadily higher returns from Health Care, the sector is in deep trouble versus Energy over the last few sessions. Biotech is definitely a factor; the IBB ETF, which tracks biotech names listed on the Nasdaq, was down over 5% as of this writing. But more broadly, Health Care is just the latest market leader to get hit; one of the reasons the chart below is so painful is the big gains in Energy, which has been a very popular short.