VV is Vanguard's large-cap U.S. equity ETF, tracking a slightly different index (CRSP Large Cap) than the S&P 500, but functioning nearly identically to VOO. Top holdings — Nvidia, Apple, Microsoft — are the same.

Its 18.8% one-year return is essentially in line with VOO's 19.0%, and the expense ratio matches at 0.03%. If you already hold VOO, there's little practical benefit to adding VV as well.