El costo real de cada operación: spread, comisión, swap y slippage
Quick answer: every trade costs you money before you are right or wrong. Four things: spread, commission, swap and slippage. At $5 per trade and two trades a day, you pay $2,600 a year — 26% of a $10,000 account. That is not a detail. For many traders it is the whole difference between profitable and flat.
Puntos clave
- You pay the cost whether you win or lose.
- The tighter your stop, the heavier the spread weighs.
- More trades is not more opportunity; it is more guaranteed cost.
- A $30 cost per trade completely erases a +0.3R edge at 1% risk.
What each cost actually is
| Costo | Qué es | Cuándo se paga |
|---|---|---|
| Spread | Gap between the buy and sell price | On entry: you start in the red |
| Comisión | Fixed charge per volume traded | On entry and on exit |
| Swap | Interest for holding a position open | Every night; one weekday charges triple |
| Slippage | Gap between requested and filled price | On fast entries, stops and news |
The first two are predictable and you can work them out today. The last two vary, which is exactly why you should measure them in your own history instead of assuming.
What does it cost me per year?
This is the table that changes decisions. A $10,000 account and a $5 total round-turn cost:
| Frequency | Trades per year | Annual cost | % of account |
|---|---|---|---|
| 4 per week | 208 | $1,040 | 10.4% |
| 2 per day | 520 | $2,600 | 26% |
| 10 per day | 2,600 | $13,000 | 130% |
That last row is not a typo. A very active scalper can pay more in costs than the size of the account in a single year. That is why scalping demands a far larger edge than swing trading: it is not competing against the market, it is competing against its own bill.
How cost eats your edge
Say your gross expectancy is +0.3R at 1% risk ($100 per trade). That is $30 gross per trade:
| Cost per trade | Net result | Net expectancy | Edge lost |
|---|---|---|---|
| $5 | $25 | +0.25R | 17% |
| $10 | $20 | +0.20R | 33% |
| $15 | $15 | +0.15R | 50% |
| $30 | $0 | 0R | 100% |
Why it hurts more with tight stops
The spread is fixed; your stop is not. The tighter you set the stop, the bigger the share of your risk the spread takes before you even start:
| Distancia del stop | 2-point spread | 5-point spread |
|---|---|---|
| 20 points | 10% of your risk | 25% of your risk |
| 50 points | 4% | 10% |
| 100 puntos | 2% | 5% |
| 200 puntos | 1% | 2.5% |
With a 20-point stop and a 5-point spread you begin every trade 25% down. You need to be right far more often just to break even.
Swap, the one nobody checks
If you hold positions for several days, swap accumulates quietly. A position at −$3 a night held for ten nights costs −$30, plus the triple-charge day. It can turn a winning trade into a flat one. Read the symbol specification and log the swap before you plan to hold anything for a week.
How to cut it without changing your strategy
- Measure first. Export 50 trades and add up the real commissions and swaps; it is almost always more than you think.
- Trade liquid hours. Spreads widen outside session and around news.
- Widen the stop or cut the lot instead of squeezing the stop to its limit.
- Trade less often. This is the most powerful lever of all: fewer trades, smaller bill.
- Compare total cost, not the advertised spread: a low-spread, high-commission account can end up worse.
The full method — the five-step cost audit, the required-win-rate tables, the swap and slippage chapters and a printable worksheet — is laid out in the free ebook The True Cost of Trading.
Point 4 is the one people resist most and the one that returns the most money. If your system trades defined signals instead of impulses, frequency controls itself: the Cortex Signal Kit gives entries with the stop and target already set, and Cortex Automation executes them in your MetaTrader 5 without adding trades you never planned. To measure it before deciding, the Automation Test runs five days.
Which is better: low spread with commission, or high spread with none?
It depends on your volume. Add both across 50 of your own real trades and compare the totals; the question cannot be answered in the abstract.
Is slippage always against me?
Not always, but it tends to be worse in high volatility — which is exactly when the most orders trigger.
How do I avoid swap?
Close before the daily rollover. If you swing trade, swap is a cost of doing business and belongs in your numbers.
Is a 2-point spread a lot?
Impossible to answer without your stop distance. With a 200-point stop it is irrelevant; with a 20-point stop it decides everything.
Do costs affect an automated system?
Exactly as much as a manual one. The difference is that an automated system pays them with perfect discipline, so include them in the backtest.
Fewer trades, better chosen. Start with the free ebook The True Cost of Trading, then see the Cortex Signal Kit and Cortex Automation.
Disclaimer: educational content. Figures are illustrative and vary by broker, symbol and market conditions. Cortex Next is not a financial service and guarantees no results. Trading involves risk of loss.
