I was extremely bullish on small-cap stocks at the start of 2025, but the S&P 500 outperformed once again.As 2025 got underway, I wrote an article referring to the Vanguard Russell 2000 ETF (VTWO 0.57%) as one of the best investments for 2025 and beyond. At the time, the benchmark small-cap index was approaching correction territory, due to market turbulence that hit smaller companies hard.Well, the ETF delivered a total return of about 13% for the year, so it's not as if this was a disastrous call by any m ...