Trading costs, fees and tax drag
Cost drag is the single most underestimated variable in retail trading. It is small per trade, relentless in aggregate, and it is charged whether the trade wins or loses.
Where the money goes
- Spread — the gap between bid and ask, paid on entry and exit.
- Commission — a flat or per-share fee at both ends.
- Slippage — the difference between the intended and executed price, worst exactly when markets move fast.
- Financing — daily interest on leveraged or margined positions.
- Taxes — short-term rates on realised gains, with no long-term relief.
Why it compounds
A trader making ten round trips a day pays that stack twenty times daily. Even a tiny per-trade cost becomes a large annual hurdle: the required gross win rate rises with frequency, while the achievable edge does not. This is exactly why the Taiwan data shows traders who look profitable gross and still finish behind a passive index net of costs.
The comparison that matters
A diversified index fund charges a fraction of a percent per year, once. That is the benchmark every active strategy must clear before it has produced anything. See is day trading worth it? for the full comparison.
What the long-run studies actually found
Five independent datasets, four countries and three decades point the same way: the share of retail day traders who make money after costs is small, and the share who make a living from it is smaller still. These are audited account records, not surveys or self-reported returns.
| Study or source | Sample | Headline finding |
|---|---|---|
| Barber, Lee, Liu & Odean | Taiwan, 1992-2006 | Under 1% of day traders earned reliably positive net profits; the top 500 covered their costs, everyone else funded them. |
| Chague, De-Losso & Giovannetti | Brazil, 2013-2015 (1,600 traders) | 3% were profitable and only 0.4% earned more than a bank teller. None who persisted improved with experience. |
| Barber & Odean, Trading Is Hazardous to Your Wealth | USA, 66,465 households | The most active fifth of accounts underperformed the market by about 6.5 percentage points a year. |
| ESMA and national regulators | EU/UK retail CFD accounts | 74-89% of retail CFD accounts lose money — a figure brokers are legally required to publish. |
| Jordan & Diltz | USA, 324 day traders | About 20% finished profitable over the period; losses were concentrated among the least experienced. |
Where the money actually goes
Before a trader beats the market, they must beat their own cost base. Every round trip pays a spread, usually a commission, and some slippage. At a realistic $8 per round trip, cost drag alone can exceed the entire account within a year.
| Trader profile | Round trips per year | Annual cost | Share of a $25,000 account |
|---|---|---|---|
| Casual — 5 trades a week | 260 | $2,080 | 8% |
| Active — 5 trades a day | 1,250 | $10,000 | 40% |
| Very active — 20 trades a day | 5,000 | $40,000 | 160% |
| Scalper — 50 trades a day | 12,500 | $100,000 | 400% |
Key terms, defined
- Day trading
- Opening and closing a position in the same instrument within one trading session, aiming to profit from short-term price movement.
- Spread
- The gap between the buy and sell price. It is an immediate, guaranteed loss at the moment a position opens.
- Leverage
- Borrowed exposure that multiplies both gains and losses. It shortens the time to ruin far more than it raises expected return.
- Slippage
- The difference between the expected fill price and the actual one, largest exactly when volatility makes trading look most attractive.
- Drawdown
- The fall from an account's peak to its trough. A 50% drawdown requires a 100% gain to recover.
- Expected value
- The average outcome of a strategy repeated many times. For retail day trading, it is negative after costs.
Frequently asked questions
Do zero-commission brokers remove the cost problem?
No. Zero-commission brokers still earn from the spread and, in some markets, from payment for order flow. The cost moves; it does not disappear.
How much does slippage matter?
More than most traders assume, because it is worst during fast markets — precisely when short-term strategies trade most.
Are taxes really that significant?
Yes. Short-term gains are taxed at the highest marginal rate in most jurisdictions, while long-term holders defer tax for years and often pay a lower rate.
Can day trading be learned with enough practice?
The Brazilian futures study followed traders day by day and found no improvement with experience: persistence increased losses rather than skill. Unlike chess or surgery, markets give noisy, delayed feedback, so practice does not reliably build expertise.
Do courses, signals or prop-firm challenges improve the odds?
There is no published evidence that paid education changes outcomes. Course fees, subscription costs and challenge fees are additional guaranteed costs added on top of an already negative expected value.
What is a realistic annual return for a retail day trader?
For the large majority it is negative after costs and taxes. A diversified index fund returned roughly 7-10% a year on average over long periods, with no screen time and far lower cost.
Read the whole argument
The arithmetic of cost drag is worked through in full in Day Trading Kills.