Generated August 8, 2026.
Overview
FSKAX is a mutual fund tracking the entire U.S. stock market across all capitalizations, while VOO is an ETF tracking just the 500 largest U.S. companies in the S&P 500. The core difference: FSKAX gives you broad market exposure—large, mid, and small caps—while VOO concentrates on large-cap stocks. That seemingly small shift in scope creates meaningful differences in cost, yield, and what you own.
How they differ
The biggest difference is breadth. FSKAX holds the whole market; VOO holds the S&P 500 only. That means FSKAX includes mid and small caps that VOO skips entirely, exposing you to different segments of the market.
Second: cost. VOO's expense ratio is 0.03% versus FSKAX's 2.01%—a 198-basis-point gap that compounds relentlessly over decades. On $100,000, that's roughly $2,000 per year in extra fees from FSKAX.
Third: yield and structure. VOO distributes 1.10% quarterly as an ETF, while FSKAX distributes just 0.01% as a mutual fund. VOO's higher yield reflects its large-cap focus; the lower FSKAX yield partly reflects holdings across smaller companies that retain earnings. VOO also has far larger assets under management at $1032B versus FSKAX's $138B, meaning tighter spreads and more price discovery.
Who each is best for
FSKAX: Fits investors seeking the broadest possible U.S. equity exposure—a pure total-market bet that includes small and mid-cap growth alongside large caps. Works well in portfolios where you want to own the entire market in a single holding.
VOO: Designed for investors whose core U.S. equity allocation focuses on large-cap stability and who prioritize minimal fees. Fits accounts where ultra-low costs and quarterly cash flow from distributions matter, and where large-cap concentration aligns with the rest of the portfolio.
Key risks to know
- Expense ratio drag. FSKAX's 2.01% annual fee versus VOO's 0.03% means FSKAX starts every year roughly 200 basis points behind on a level playing field. Over 20 years, that fee difference alone can reduce returns by 20% or more before accounting for tax drag or reinvestment timing.
- Market-cap overlap and timing. Both funds hold large-cap stocks, so they overlap significantly. FSKAX's additional mid and small-cap holdings expose you to a different volatility profile; if large caps outperform, FSKAX will lag due to its broader weighting.
- Mutual fund versus ETF structure. FSKAX is a mutual fund with a fixed share price ($213.98); VOO is an ETF with intra-day trading. If you trade FSKAX, you settle at end-of-day NAV; VOO prices continuously. For buy-and-hold investors this is immaterial, but for those who trade frequently, VOO offers more flexibility.
Bottom line
If you want the absolute lowest-cost broad market exposure and are comfortable limiting yourself to large caps, VOO's 0.03% expense ratio is difficult to beat. If you want true total-market exposure across all capitalizations and are willing to accept higher fees for broader coverage, FSKAX delivers that breadth—though its 2% fee is high by index-fund standards. Neither fund's past performance predicts future results; what matters here is the fee structure and the stocks you'll own.
AI-generated analysis for educational purposes only. Verify important details independently; past performance does not guarantee future results.
