When choosing a fund for your child's 530A account, the expense ratio is one of the few knobs you actually control. Everything else — market returns, the $1,000 deposit, the tax treatment — is fixed. This guide explains what an expense ratio is, how it compounds, and when the differences between low-cost index funds actually matter.
What Is an Expense Ratio?
An expense ratio is the annual fee a fund charges to manage your money, expressed as a percentage of assets under management. A 0.03% expense ratio means the fund deducts $0.30 per year for every $1,000 invested. The fee is subtracted automatically from the fund's net asset value — you never see a separate charge on your statement, but the money still comes out of your balance.
There are two things that make expense ratios particularly important inside a 530A:
- You can't offset them with deductions. Unlike a taxable brokerage, there's no tax-loss harvesting or fee deduction to compensate. Every basis point is a straight subtraction.
- They compound against you. A 0.03% fee in year one is a 0.03% fee on a larger balance in year two, which compounds against even more in year three. Over 18 years, the drag accumulates in a way a single-year comparison doesn't capture.
Comparing Popular Low-Cost Funds
The major brokerages all offer essentially-identical S&P 500 or total-market index funds. The expense ratios are small, but they're not the same:
| Fund | Ticker | Expense Ratio | Tracks |
|---|---|---|---|
| Fidelity Zero Total Market | FZROX | 0.00% | Total U.S. market |
| Fidelity Total Market | FSKAX | 0.015% | Total U.S. market |
| Schwab S&P 500 | SWPPX | 0.02% | S&P 500 |
| Vanguard S&P 500 | VOO | 0.03% | S&P 500 |
| Fidelity 500 | FXAIX | 0.015% | S&P 500 |
| Robinhood default | — | ~0.03% | S&P 500 |
A few notes on what these tickers are and aren't:
- FZROX is the cheapest fee but has a catch. Fidelity's "Zero" funds are proprietary — you can hold them at Fidelity but cannot transfer them to another broker. If you ever want to roll the 530A to Schwab or Vanguard, Fidelity will sell FZROX and convert it to cash before transferring.
- FSKAX and FXAIX are effectively free and portable. Both transfer in-kind to any brokerage. FSKAX is total market (all ~4,000 U.S. stocks); FXAIX is just the S&P 500 (~500 companies). Over 18 years, the performance gap between them is small.
- VOO and FXAIX track the same index. VOO costs 0.03%, FXAIX costs 0.015%. Same stocks, same returns, half the fee.
The Math, Over 18 Years
Here's how expense ratios play out at a 7% average annual return, starting with the $1,000 seed deposit and adding $1,000/year:
| Expense Ratio | Final Balance | Total Fees |
|---|---|---|
| 0.00% | $35,010 | $0 |
| 0.015% | $34,950 | ~$60 |
| 0.03% | $34,900 | ~$110 |
| 0.04% | $34,860 | ~$150 |
| 0.10% | $34,660 | ~$350 |
| 0.50% | $32,810 | ~$2,200 |
The spread between 0.015% and 0.04% is about $90 over 18 years — roughly five dollars a year. Meaningful in aggregate, but not enough to lose sleep over.
The spread between 0.04% and 0.50% is $2,050. Now you're talking about real money. This is why low-cost index funds exist and why actively managed funds (typical expense ratio 0.50%–1.00%) are a poor fit for long-horizon accounts like this.
The Larger-Balance Scenario
If the account is maxed out at $5,000/year contributions instead of $1,000/year, the math scales with it:
- 0.015% expense ratio: Final value ~$173,800
- 0.04% expense ratio: Final value ~$173,300
- 0.50% expense ratio: Final value ~$163,100
Even here, the difference between the two cheapest tiers is under $500. The jump to an actively managed fund costs over $10,000.
Estimates assume a 7% average annual return (roughly the long-run S&P 500 return after inflation). Not a guarantee — all investing involves risk, including possible loss of principal.
When the Difference Matters
Obsessing over 0.015% vs. 0.03% is financially pointless for most 530A accounts. But there are three scenarios where expense ratios should drive your decision:
- You're comparing index vs. actively managed. If the "default" fund at your broker is 0.40% or higher, switch to an index fund. The $2,000+ difference over 18 years is real.
- You're rolling over and the receiving brokerage has a proprietary high-fee default. Some brokerages default you into a "managed portfolio" at 0.30%–0.50%. Check the expense ratio of whatever you land in.
- You're maxing contributions. At $5,000/year, every basis point scales up. The dollar stakes are still modest, but it's worth spending five minutes to pick the cheaper of two equivalent funds.
When the Difference Doesn't Matter
- Between FSKAX, FXAIX, VOO, and SWPPX. These all land in the 0.015%–0.03% band. The total fee difference over 18 years is under $100. Pick the one at your broker of choice and move on.
- Between S&P 500 and total-market. Different funds, similar long-run returns. This is a preference call, not a cost call.
- At very small account sizes. A $1,000 balance paying 0.03% is $0.30/year. Not worth optimizing.
How to Check a Fund's Expense Ratio
Every brokerage lists it prominently on the fund's detail page, usually near the ticker at the top. You can also search the fund ticker on Morningstar, Yahoo Finance, or the fund issuer's website. If you can't find it in under 30 seconds, that's a red flag — low-cost funds don't hide their fees.
Common Questions
Is the Robinhood default fund's fee negotiable?
No. Expense ratios are set by the fund issuer, not the brokerage holding the fund. The Robinhood 530A default is an S&P 500 index fund at ~0.03%, which is competitive. If you want lower, you'd need to roll over to another brokerage and pick a cheaper fund.
Do expense ratios compound like returns?
Effectively, yes. Every year the fee is applied to a slightly larger balance, so the dollar cost grows over time even if the percentage stays flat. The "total fees" column in the table above reflects this compounding drag.
Should I pick a total-market fund or an S&P 500 fund?
For an 18-year time horizon, the difference is small. Total-market (FSKAX, FZROX) includes mid-cap and small-cap stocks in addition to the S&P 500's large-caps, which adds slightly more diversification. S&P 500 funds (FXAIX, VOO, SWPPX) are simpler and have historically tracked very closely. Either is a reasonable 530A default.
What about international diversification?
Some investors prefer to add a total-international-stock fund (like FTIHX at 0.06%) for 20–40% of the allocation. This is a preference call — U.S.-only has outperformed over the last 15 years; international may catch up. For a simple, hands-off 530A, a single total-market or S&P 500 fund is fine.
Can expense ratios change?
Yes, but they rarely go up. Competition between Vanguard, Fidelity, and Schwab has driven fees steadily downward for 20 years. If anything, expect the default to get cheaper over time, not more expensive.
The Bottom Line
The expense ratio matters, but not as much as people think. The difference between 0.015% and 0.03% over 18 years is around $90 on a $1,000-contribution account — real but small. The difference between 0.03% and 0.50% is over $2,000 — large enough to act on.
Pick an index fund from Fidelity, Schwab, or Vanguard in the 0.00%–0.04% range, contribute what your budget allows, and don't overthink it. For the specific case of deciding whether to stay at Robinhood or move the account, see Should I Keep the Robinhood Account?. To model how contributions and fees interact, use the Growth Calculator.
This article is general educational information, not investment advice. All investing involves risk, including possible loss of principal.