The 30-second answer
A benchmark is a market index or portfolio you measure your investment against. The S&P 500. The Nasdaq. The Russell 2000. The Bloomberg Aggregate Bond Index. Each is a published, rules-based portfolio that represents a specific slice of the market.
When someone says a fund returned "12%, alpha 2%," what they mean is: the fund returned 12%, the benchmark returned 10%, and the 2-percentage-point gap is the alpha.
Picking the right benchmark matters more than most people realize. Pick the wrong one and you'll either flatter a mediocre strategy or undersell a great one.
The benchmarks you should know
A few that come up most often:
S&P 500. 500 large US companies. The default for US large-cap stocks. ~80% of US equity by market cap. Total Return version (SPXTR) includes reinvested dividends; price-only version (SPX) doesn't. Always use Total Return for comparisons.
Nasdaq Composite / Nasdaq-100. Tech-heavy. The Composite includes ~3,000 names, the Nasdaq-100 is the 100 largest non-financial Nasdaq names. Don't use these as a benchmark for diversified portfolios, they're too tech-concentrated.
Russell 2000. Small-cap US stocks (companies ranked 1,001-3,000 by market cap). Used for evaluating small-cap funds.
Russell 3000. Total US stock market. Captures essentially all investable US equities.
MSCI EAFE. Developed international stocks (Europe, Australasia, Far East). Used for international developed-market funds.
MSCI Emerging Markets. Emerging markets equity benchmark.
Bloomberg US Aggregate Bond Index. US investment-grade bond market. Used for fixed-income funds.
60/40 portfolio. Not a single index but a common benchmark: 60% S&P 500, 40% bond aggregate. Used for evaluating balanced or "moderate risk" portfolios.
The right benchmark depends on what you're holding
This sounds obvious, but plenty of fund marketing makes the comparison wrong.
A US large-cap stock portfolio should be benchmarked against the S&P 500 Total Return. Comparing it to the Dow (only 30 stocks, price-weighted, weird) or the price-only S&P (excludes dividends) is misleading.
A US small-cap portfolio should be benchmarked against the Russell 2000. Comparing it to the S&P 500 over a period when small-caps led would flatter; comparing it during a large-cap-led period would mislead in the other direction.
A balanced 60/40 portfolio should be benchmarked against a weighted blend of stock and bond indices, not just one or the other.
A sector-specific fund should be benchmarked against its sector index. A tech fund vs the Nasdaq, not the S&P 500.
An international fund should be benchmarked against the international index, not the S&P 500. They're different markets with different return profiles.
If a fund's benchmark seems oddly chosen, too easy, too hard, mismatched, that's often a clue.
Why active funds sometimes pick the wrong benchmark on purpose
This is a real practice. A fund manager whose strategy can't beat its natural benchmark might quietly switch benchmarks to one that's easier to beat.
A small-cap value fund might benchmark against the Russell 2000 (the broad small-cap index) instead of the Russell 2000 Value (the small-cap-value index, harder to beat). The fund's outperformance against the broader index could look impressive, while its underperformance against its actual style index gets buried.
When evaluating any fund:
- Read the benchmark in their materials carefully
- Compare to the right index for the strategy, not just the one they chose
- Check long windows (10+ years) to filter out luck
Total Return vs Price Return, say it again
Most published "S&P 500" charts are the Price Return index (SPX). Most fund returns are quoted on a Total Return basis (which includes reinvested dividends).
Comparing "the fund returned 12%" against "the S&P returned 10%" can be misleading if "the S&P" is the price-only number. The Total Return S&P over the same window might be 12.5%, in which case the fund underperformed.
Always compare apples to apples: Total Return to Total Return. The S&P 500 Total Return symbol is ^SP500TR on Yahoo Finance and SPXTR in many systems.
What benchmarks tell you (and don't tell you)
A benchmark answers: "Did this strategy beat a passive alternative?"
A benchmark doesn't tell you:
- Whether the strategy is appropriate for your goals
- Whether the strategy will keep working in the future
- Whether the risk taken justifies the return earned (you need risk-adjusted measures like Sharpe and Sortino for that)
- Whether the manager has any actual skill (you need a long track record and a clear thesis to assess that)
A fund that beat its benchmark by 0.5% over 5 years probably has no real skill, that's within the range of luck. A fund that beat its benchmark by 3% over 20 years probably does, though the question of whether the edge will persist is a separate one.
How we use benchmarks at Advising Alpha
Every portfolio we publish uses the S&P 500 Total Return (SP500TR) as its primary benchmark, because all our portfolios are US large-cap concentrated equity. That's the natural comparison.
Each portfolio's detail page shows:
- The growth of $10K in the portfolio vs. $10K in the S&P 500 TR over the same window
- Year-by-year returns of both, side by side
- The alpha (portfolio return minus benchmark return) for each year and for the full period
- The Sharpe and Sortino ratios for both, so you can see risk-adjusted performance
This level of transparency is unusual. Most fund pages quote a single trailing return without showing the full benchmark history. Showing the entire side-by-side record makes the comparison hard to fudge.
Multiple benchmarks for the same strategy
For some strategies, looking at multiple benchmarks is informative.
A concentrated 20-stock US large-cap portfolio might be compared to:
- S&P 500 Total Return: the broadest, most natural benchmark
- S&P 500 Equal Weight: closer to how the strategy is constructed (equal-weighted)
- Russell 1000 Value or Russell 1000 Growth. depending on style tilt
- A custom blended benchmark. often used by institutional investors with specialized strategies
If a fund beats one benchmark but loses to another, that's important information. Beating the cap-weighted S&P 500 while losing to the equal-weighted version, for example, suggests the fund's outperformance is just a side effect of equal-weighting and might be replicable cheaper through an equal-weight ETF.
What this means for you
When you're evaluating any portfolio, fund, or strategy:
- Identify the right benchmark for the strategy (not just whatever the fund picked)
- Use Total Return, not Price Return
- Compare across long windows (10+ years minimum)
- Look at risk-adjusted performance (Sharpe, Sortino), not just raw alpha
- Be skeptical of strategies that change benchmarks over time: that's often a tell
The right benchmark for most US-focused individual investors is the S&P 500 Total Return. If your portfolio doesn't beat that index over decades, the right answer is usually to just buy the index and stop trying.
We publish our portfolios with that comparison front and center, on every detail page. Because if we couldn't beat the index, you should know.