TL;DR: Small-Cap ETFs in 5 Points
- A small-cap ETF holds shares of companies worth roughly $300 million to $2 billion. These are smaller businesses that move faster and fall harder than household names.
- Small-caps have outperformed large-caps by roughly 2-3% per year over long periods, but with more volatility. You earn more by tolerating more chaos.
- VB (0.05%) and SCHA (0.04%) are the two cheapest broad small-cap ETFs. They're nearly identical. Schwab costs one basis point less.
- If you own VTI, you already have small-cap exposure: about 7% of the fund. A dedicated small-cap ETF is a deliberate tilt, not a gap-fill.
- AVUV is the fund serious small-cap investors argue about. It targets small-cap value specifically, which has an even stronger historical premium than small-cap alone.
What Is a Small-Cap ETF?
Market cap is the total dollar value of a company's outstanding shares. A company trading at $50 per share with 20 million shares outstanding has a $1 billion market cap. Small-cap means the company's total market value sits roughly between $300 million and $2 billion, depending on which index you use.
A small-cap ETF holds hundreds of these companies at once. Instead of betting on whether any single small business grows into a large one, you own the whole category. Some will fail. Some will become the next mid-cap or large-cap darling. Historically, enough of them succeed that the category as a whole delivers better long-run returns than owning only large companies.
Apple, Microsoft, and Amazon are mega-caps, worth trillions. They dominate the S&P 500. A total market fund like VTI includes them and gives you exposure all the way down to the smallest publicly traded companies, but large-caps still drive the returns because they make up the most weight.
Small-cap ETFs cut out the giants and give you concentrated exposure to the smaller end.
Why Small-Caps Have Outperformed, and Why That Doesn't Guarantee Anything
From 1926 to 2022, U.S. small-cap stocks returned roughly 11.8% annually versus 10.1% for large-caps, according to Dimensional Fund Advisors research based on CRSP data. That 1.7% annual gap compounds into a meaningful difference over 30 years.
The academic explanation is risk. Small companies are less stable than large ones. They have thinner margins, less access to capital, and more exposure to economic downturns. Investors demand extra return for holding something riskier. The extra return you earn from small-caps is compensation for the extra volatility you accept.
The honest caveat: that premium doesn't show up every year, or even every decade. U.S. large-caps significantly outperformed small-caps from 2013 to 2021, an eight-year stretch where the historical playbook looked wrong. Investors who loaded up on small-caps during that period earned less than those who held the S&P 500. The premium is real over very long periods. It is not reliable over any particular five-year window you pick.
Most investors who add a small-cap ETF based on the historical return data end up abandoning the position during a stretch of underperformance. If you wouldn't hold a fund through a three-year period where it trails VTI by 5% per year, you shouldn't own it. The premium requires patience to collect.
The Four Small-Cap ETFs Worth Knowing
The largest dedicated small-cap ETF by assets. The CRSP index extends into mid-cap territory. About 30% of VB's holdings are technically mid-caps. If pure small-cap exposure matters to you, VB is less concentrated than its name implies. For most buy-and-hold investors, that distinction doesn't matter much.
One basis point cheaper than VB. Slightly more holdings, slightly more diversified. For buy-and-hold investors, the practical difference between SCHA and VB is negligible. Choose based on your brokerage: Vanguard customers default to VB, Schwab customers to SCHA.
IJR tracks the S&P SmallCap 600, which has a quality screen: companies must pass earnings tests to be included. That filter means IJR holds fewer but more profitable small-caps than VB or SCHA. It has underperformed VB over most 10-year periods in calm markets, but held up better during economic stress. Worth considering if you want higher-quality small-caps specifically.
This one is different. AVUV doesn't just own small-caps: it targets small-cap value stocks specifically. It screens for small companies trading at low price-to-book with high profitability ratios. Academic research by Fama and French identified small-cap value as having the strongest historical return premium of any factor. AVUV launched in 2019 and has outperformed VB since inception, though the sample is short. Compare AVUV against VBR (Vanguard's small-cap value fund) in our AVUV vs VBR comparison.
| ETF | Expense Ratio | Holdings | Strategy | Best For |
|---|---|---|---|---|
| VB | 0.05% | ~1,400 | Broad small-cap blend | Vanguard investors |
| SCHA | 0.04% | ~1,800 | Broad small-cap blend | Most investors |
| IJR | 0.06% | ~600 | Quality-screened small-cap | Quality focus |
| AVUV | 0.25% | ~750 | Small-cap value factor | Factor investors |
Small-Cap Blend vs. Small-Cap Value
VB, SCHA, and IJR are small-cap blend funds. They own small-caps across the growth-value spectrum.
AVUV is a small-cap value fund. It deliberately tilts toward cheaper companies by valuation metrics.
The argument for small-cap value: Fama-French research and its extensions consistently found that small cheap stocks outperformed small expensive stocks over long periods. Fama and French estimated the combined small-cap value premium at roughly 4-5% annually over their full sample, compared to approximately 3% for size alone.
The argument against AVUV for most investors: it charges 0.25% versus 0.04% for SCHA. It requires conviction in factor investing. You need to believe the premium will persist and hold through the periods when it doesn't. From 2017 to 2020, small-cap value underperformed significantly. Many investors who had added it gave up near the bottom.
AVUV is worth owning for investors who understand factor investing and won't abandon it during the dry spells. For everyone else, SCHA at 0.04% captures the size premium without requiring a conviction thesis about value. Buying AVUV because it "sounds more sophisticated" is a good way to sell at the worst time.
If You Own VTI, You Already Have Small-Caps
VTI tracks the CRSP U.S. Total Market Index, which covers about 3,900 companies across every size. But it's market-cap weighted. The largest companies get the most weight. Apple alone represents about 6% of VTI. The entire small-cap sleeve of VTI is roughly 7% of the fund.
That 7% is real exposure. It's not zero. But it means small-cap moves barely register in a VTI-only portfolio. If SCHA drops 20%, VTI might drop 1.5% from that alone.
Adding a dedicated small-cap ETF to a VTI portfolio tilts your portfolio toward smaller companies. You're overweighting them relative to their share of the total market. That's a deliberate bet. Not a correction.
A 5% allocation to SCHA alongside VTI doesn't move the needle much. A 20-30% allocation will noticeably affect your results in both directions.
When a Small-Cap ETF Makes Sense
Small-cap ETFs make sense for investors with a long runway who can hold through drawdowns without blinking. The specifics matter.
If you're in your 20s or 30s building a portfolio from scratch and won't need the money for 25+ years, a 15-25% allocation to a small-cap ETF alongside a broad market fund is a defensible strategy.
If you're within 10 years of retirement, skip it. The added volatility creates sequence-of-returns risk: a deep small-cap drawdown the year before you need to start withdrawing is a real problem. Stick to broad market funds.
If you're already holding a three-fund portfolio (VTI, VXUS, BND), adding a small-cap fund increases complexity without obviously improving the portfolio for most investors. The case for adding it requires conviction that the size premium will persist and that you'll maintain the allocation through the inevitable dry spells.
The Honest Case for Skipping Small-Caps Entirely
VTI includes small-caps. It's cheap, diversified, and requires no conviction about factors. Most investors who try to tilt toward small-caps eventually abandon the tilt during a rough period and end up with a worse outcome than if they'd just held VTI.
The factor premium literature is strong. But it's based on long historical periods and assumes you hold through bad stretches without blinking. Most investors don't.
If you're skeptical about your ability to hold a small-cap tilt through a three-year underperformance stretch, VTI alone is a better choice than SCHA-plus-VTI that you'll abandon at the wrong time.
For most investors: VTI, held forever, is better than VTI plus SCHA that you'll second-guess every time small-caps lag. The size premium is real. Collecting it requires conviction most people don't actually have. Know yourself before you add the tilt.
Frequently Asked Questions
ETFs Mentioned in This Guide
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