Small-cap equities could be the dark horse of the next 10 years after the previous decade saw an outsized return from the U.S. large-cap sector. The latest Vanguard market perspective highlights the U.S. small-cap sector as the leading domestic opportunity, projecting an annualized return between 5% and 7%, with a caveat of the median volatility of 22.6% — the highest among the listed domestic sectors.