1% is not 1%: why the minimum lot quietly breaks small-account risk
Most of us size trades the same way: risk 1% of the balance, put the stop where the chart says, and let the calculator give the lot. The calculator does its job. The broker then does its job too: it rounds the lot to the lot step and never goes below the minimum lot. On a small account that second step can turn 1% into 8%, and nothing on the screen says so.
The minimum lot does not care about your plan
Take gold, XAUUSD, with a typical contract of 100 ounces per lot. The minimum lot is 0.01, which is one ounce: every dollar the price moves is one dollar of profit or loss. Here is what that single minimum lot risks at three ordinary stop distances:
| stop distance | loss at 0.01 lot | on $300 | on $1,000 | on $10,000 |
|---|---|---|---|---|
| $5 | $5 | 1.67% | 0.50% | 0.05% |
| $10 | $10 | 3.33% | 1.00% | 0.10% |
| $25 | $25 | 8.33% | 2.50% | 0.25% |
On $300 with a $25 stop, 1% is $3. The lot that would risk exactly $3 is 0.0012, which no broker accepts. The smallest lot you can open is 0.01, so the trade really risks $25, or 8.33%, more than eight times the plan.
Two numbers that tell the truth
Instead of asking "what lot does my risk allow?", ask two other questions before the entry:
- What balance does an honest 1% need at this stop? It is the loss of one minimum lot divided by 1%. For gold at a $25 stop: $25 / 0.01 = $2,500. Below that balance, 1% at this stop is simply not possible.
- What is the widest stop that keeps 1% at the minimum lot? It is your 1% in money divided by what one point costs at the minimum lot. On $300: $3 / $1 per dollar = a $3.00 stop.
If neither answer fits the trade, the honest options are a smaller stop, a larger account, or no trade. Not a bigger risk by accident.
Rounding adds its own error
Even above the minimum lot, the lot step rounds every size. With $2,580 and a $16 gold stop, 1% allows 0.0161 lots. Rounding down gives 0.01 lot and 0.62% risk. Rounding to the nearest step gives 0.02 lot and 1.24%, that is, 24% more risk than you set. Know which one your tool uses.
The spread and the commission are part of the loss
A market buy fills at the Ask, but the stop is triggered by the Bid. The spread is therefore inside your stop distance. On our test server, gold quoted 3,997.82 / 3,998.16, a spread of $0.34. On a $25 stop that is 1.4% of the loss; on a $5 scalping stop it is 6.8%. Commission is added on top: a broker charging $7 per lot round trip adds $0.07 to a 0.01-lot trade.
When the account currency is the pair's base currency
On USDJPY with a USD account, profit and loss are made in yen and converted into dollars at the closing price. Tick value is usually quoted at today's price, but your stop closes at the stop price. In our tests, a buy with a stop 2% below the price produced a loss about 2% larger than a tick-value estimate predicted (101.99 instead of 100.00 dollars for 0.05 lots). The terminal's own profit calculation at the stop price gets it right; a simple tick-value formula does not.
A short checklist before every entry
- The lot you can open, not the lot you would like: is it the minimum lot?
- The risk after rounding, not before.
- The spread now, inside the stop distance.
- Commission per lot, round trip.
- On pairs like USDJPY, the loss at the stop price, not at today's price.
- If the real risk is more than the plan: move the stop, wait, or skip.
One percent is a promise you make to your account. It only holds if the number you see is the number you will lose.
