As the first quarter of 2021 draws to a close, U.S. stock funds are recording eye-popping one-year returns. Over 2,000 U.S. equity funds finished March up 50% or more from a year ago. While certainly striking, investors should take these returns with a grain of salt, and the situation highlights a major quirk in shorter-term rolling returns. Essentially, the returns reflect the combination of sharply lower stock market prices during the coronavirus-related market collapse one year ago and the subsequent strong rebound, resulting in what appear to be outsize returns. In addition, when these big fund returns are put in context of a comparison benchmark, their performance is much less impressive. For example, the Morningstar US Market Index is up roughly 58% from a year ago. This reflects the importance of selecting and looking at performance relative to a benchmark.