By WealthIQ Editorial
Last Updated: March 2026
Executive Summary
- The S&P 500 has delivered roughly 13.5% annualized over the last decade; low-cost index funds are the most proven vehicle to capture those returns.
- Expense ratios matter: a 1% fee vs 0.03% on a $100,000 portfolio costs over $27,000 in lost returns over 20 years.
- VOO, FXAIX, and IVV are functionally identical S&P 500 trackers — your choice depends on your broker.
- Total market funds (VTI, FSKAX) offer slightly broader diversification by including small- and mid-cap stocks.
Bottom line: For most investors, a simple two-fund portfolio of VTI + VXUS (or the Fidelity equivalent) covers the entire global stock market at near-zero cost.
Why Index Funds Beat Most Active Funds
Before picking specific funds, the case for indexing deserves a brief review. According to the SPIVA Scorecard (S&P Dow Jones Indices), over the 15 years ending 2024, approximately 88% of large-cap active funds underperformed the S&P 500. The longer the time period, the worse active managers look relative to passive indexes.
The reasons are structural: active funds charge 0.5–1.5% in fees, need to generate trades (triggering taxes), and require portfolio managers to consistently make correct calls — a feat that becomes statistically near-impossible over long periods. Index funds simply buy the market and sit.
Top 10 Index Funds for 2026
| Ticker | Index Tracked | Expense Ratio | 10-Yr Ann. Return* | Min. Investment | Best For |
|---|---|---|---|---|---|
| VOO | S&P 500 | 0.03% | 13.1% | $1 (fractional) | Vanguard / most brokers |
| FXAIX | S&P 500 | 0.015% | 13.1% | $1 | Fidelity account holders |
| IVV | S&P 500 | 0.03% | 13.1% | $1 (fractional) | iShares / TD Ameritrade |
| VTI | CRSP US Total Market | 0.03% | 12.8% | $1 (fractional) | Broad US market exposure |
| FSKAX | Fidelity US Total Market | 0.015% | 12.7% | $1 | Fidelity total-market option |
| VXUS | FTSE Global All Cap ex-US | 0.07% | 5.1% | $1 (fractional) | International diversification |
| BND | Bloomberg US Aggregate Bond | 0.03% | 1.5% | $1 (fractional) | Conservative / near-retirement |
| SCHD | Dow Jones US Dividend 100 | 0.06% | 11.4% | $1 (fractional) | Income + total return hybrid |
| QQQ | Nasdaq-100 | 0.20% | 17.5% | $1 (fractional) | Tech-heavy growth tilt |
| SWTSX | Dow Jones US Total Market | 0.03% | 12.6% | $1 | Schwab account holders |
*10-year annualized returns approximate as of early 2026. Past performance does not guarantee future results. Source: fund provider fact sheets.
S&P 500 Funds: VOO vs FXAIX vs IVV
These three are the workhorses of passive investing. All track the S&P 500, all deliver nearly identical returns, and all charge almost nothing. The deciding factor is almost always your brokerage:
- VOO (Vanguard S&P 500 ETF): Best if you have a Vanguard account or want the ETF structure. Commission-free at all major brokers. 0.03% expense ratio.
- FXAIX (Fidelity 500 Index Fund): The cheapest of the three at 0.015%. Only available as a mutual fund (not ETF), which means it settles at end-of-day NAV — fine for long-term investors. Best if you bank at Fidelity.
- IVV (iShares Core S&P 500 ETF): Owned by BlackRock. Same 0.03% as VOO. Slightly higher trading volume and tighter bid-ask spreads, which marginally matters for large trades. Best for Schwab or TD Ameritrade users.
Bottom line: the performance difference between these three over 30 years is statistically negligible. Pick the one your broker offers for free and move on.
Total Market Funds: VTI and FSKAX
The S&P 500 covers the 500 largest US companies — roughly 80% of total US market cap. Total market funds add the remaining 20% of small- and mid-cap stocks. Historically, the return difference is minimal (VTI has slightly outperformed VOO in some decades due to small-cap premiums). The argument for total market funds:
- You own essentially every publicly traded US company — true market exposure
- Small-cap stocks have historically provided a long-term premium over large-caps (the “small-cap effect”)
- Same ultra-low costs as S&P 500 funds
VTI holds ~3,700 stocks vs VOO’s 500. FSKAX is Fidelity’s equivalent at 0.015% — one of the cheapest total-market funds available.
International Diversification: VXUS
The US represents about 60% of global market cap, but holding only US stocks means you’re betting entirely on one country’s economic trajectory. VXUS covers the other 40% — developed markets like Europe, Japan, and the UK, plus emerging markets like China, India, and Brazil.
Arguments for international exposure:
- Valuation: as of early 2026, international stocks trade at significantly lower P/E ratios than US stocks
- Currency diversification reduces US-dollar concentration risk
- Historically, US and international markets cycle in leadership — international stocks outperformed US in 2002–2007 and other periods
A common allocation: 80% VTI + 20% VXUS, or the equivalent Fidelity combo (FSKAX + FTIHX).
Dividend Index Funds: SCHD
SCHD tracks 100 high-quality US dividend-paying stocks screened for dividend growth, payout ratio, and financial strength. It is not a yield-chasing fund — it’s a quality filter. As of early 2026, SCHD yields approximately 3.5% and has grown its dividend by an average of 11.3%/year over the past decade.
SCHD is appropriate for investors who:
- Want income without overweighting utilities or REITs
- Are in or near retirement and want growing income
- Prefer a dividend-growth strategy alongside a core total-market holding
It is not a substitute for a total-market fund for younger, growth-focused investors.
Bond Funds: BND
BND holds over 10,000 investment-grade US bonds — Treasuries, agency bonds, and corporate bonds. It’s the default “safe” portion of most three-fund portfolios. As of early 2026, BND yields approximately 4.8% and has a duration of about 6 years, meaning a 1% rise in rates would reduce its price by ~6%.
General guidance on bond allocation: subtract your age from 110 to get your equity percentage. A 40-year-old might hold 70% stocks / 30% bonds. However, in prolonged low-rate environments, many advisors recommend holding fewer bonds at younger ages.
Building a Simple Index Fund Portfolio
You don’t need 10 funds. Here are three battle-tested portfolios based on complexity preference:
The One-Fund Portfolio
VT (Vanguard Total World) — one fund covering every publicly traded stock on Earth. 0.07% expense ratio. Set it and forget it.
The Two-Fund Portfolio (Recommended for Most)
80% VTI + 20% VXUS (or FSKAX + FTIHX at Fidelity). Total global equity exposure at near-zero cost.
The Three-Fund Portfolio
60% VTI + 20% VXUS + 20% BND. Classic Bogleheads allocation. Add bonds based on age and risk tolerance.
Which Broker Should You Use?
For pure index fund investing:
- Fidelity: Best overall — zero-expense-ratio funds (FZROX, FZILX), fractional shares, excellent customer service. Open a Fidelity account.
- Vanguard: The originator of index funds; best if you want mutual fund share classes for simplicity.
- Schwab: Strong platform, SWTSX is a great total-market option, and Schwab’s banking integration is excellent.
- Robinhood: Good for commission-free ETF trading; limited mutual fund access. Try Robinhood.
The Bottom Line
The best index fund is often simply the one with the lowest expense ratio at your brokerage. For most investors, the choice boils down to: pick VTI or FXAIX for US exposure, add VXUS or FTIHX for international, and consider BND as you approach retirement. Then automate contributions and stop checking daily. The data — and decades of academic research — strongly favor this approach over stock-picking or market-timing.