SPLV tracks the S&P 500 Low Volatility Index, which holds the 100 S&P 500 stocks with the lowest trailing 12-month volatility and weights each inversely to its volatility. The portfolio is concentrated in defensive sectors such as utilities, consumer staples, healthcare and financials, with little technology, and it is rebalanced quarterly. The fund has tended to fall less than the broad market in sharp declines and lag in strong rallies. Because it holds many interest-rate-sensitive sectors, it can fall when rates rise quickly.