Prop-firm drawdown: calculate the real risk budget before every trade

1. Nominal account size is not loss capital

An account marketed as “50K” may start at $50,000 while becoming ineligible after a $2,000 or $2,500 decline, depending on the program. The headline number is a calculation base or buying-power label. For sizing, the useful number is the distance to the threshold that triggers violation, liquidation or lockout.

2. Static, end-of-day trailing and intraday trailing drawdown

Static drawdown

The threshold is fixed from starting capital and does not rise as the account gains. With $100,000 and a $10,000 static maximum loss, the floor remains $90,000 unless payout or reset terms say otherwise.

End-of-day trailing drawdown

The threshold follows a reference updated at a defined time, often the highest end-of-day balance. It rises after a new high close and generally never falls. Some programs eventually lock it at starting balance or another value.

Intraday or equity trailing drawdown

The threshold may follow a realized or unrealized peak during the session. An open gain that disappears can shrink room even though no gain was banked. This is highly path-dependent and must never be treated as end-of-day trailing without written confirmation.

3. Know whether the rule monitors balance, equity or net P&L

A rule may observe closed balance, real-time equity or Net P&L including open positions. FTMO, for example, defines relevant equity using balance plus open-position P&L, swaps and commissions. Topstep states that its Maximum Loss Limit can be touched by unrealized P&L even if the final fill leaves balance above the threshold.

• Balance: closed results according to the platform’s definition.
• Equity: balance adjusted by open P&L and potentially other costs.
• High-water mark: the highest historical value of the chosen metric.
• Violation threshold: the current level that cannot be touched or crossed, as wording specifies.
• Buffer: voluntary room above the threshold, not a provider guarantee.

The verb matters: some rules fail when equity touches the line, not only when it closes below. Sizing exactly to the threshold leaves no room for spread, slippage or fees.

4. Calculate remaining daily-loss capacity

A daily limit can restart from a balance captured at a specific time or use a fixed amount. It may count closed losses, unrealized P&L, commissions and swaps. The provider’s “day” is not necessarily midnight in your local timezone.

If the rule includes unrealized P&L, consumed daily loss changes while positions remain open. A profitable position carried through reset can also affect the next day’s reference under some formulas.

• Record reset time and timezone, including daylight-saving transitions.
• Check how open positions are handled at reset.
• Include commissions, swaps and fees when the rule includes them.
• Distinguish a session lockout from a permanent account violation.

5. Effective budget formula for a new trade

Do not necessarily subtract the same buffer twice in aggregate tracking; model it explicitly. Buffer size depends on contract count, volatility, liquidity, news, spread and forced-liquidation mechanics. It reduces the chance of an accidental touch but cannot eliminate it.

6. Worked example: only $75 remains

Using the futures guide’s MNQ trade—45-point stop, one point of slippage, $2 point value and $1.20 fees—one contract costs about $93.20 at the stop. Because $93.20 already exceeds $75 before any buffer, compliant size is zero.

Shortening the stop solely to force one contract reverses the risk process. The stop should express thesis invalidation; if that invalidation costs too much, the trade does not fit the account in its current state.

7. Official examples show why rules are not interchangeable

Topstep: Maximum Loss Limit and unrealized P&L

In documentation checked August 21, 2026, Topstep describes a Trading Combine Maximum Loss Limit that trails end-of-day balance, never moves down and locks when it reaches starting balance. The current threshold can still be hit intraday by Net P&L including unrealized losses, triggering immediate liquidation under that documentation.

FTMO: different 1-Step and 2-Step formulas

FTMO’s official objectives page checked on the same date describes a 1-Step Maximum Daily Loss of 3% of Initial Simulated Capital recalculated at 00:00 CE(S)T, plus a 10% end-of-day trailing Maximum Loss. Its 2-Step Maximum Loss is described as static at 10%. These are dated examples, not terms to copy to another product or provider.

8. Add open risk and correlation

Different positions can depend on the same market factor. Long NQ and long ES are not two independent risks. Simply adding their stop losses may be conservative but crude; treating them as unrelated can be dangerous.

• Track stop risk on every open position.
• Group related directional exposure such as equity indices, dollar, rates or energy.
• Use a conservative correlation assumption when evidence is weak.
• Recalculate after stop changes, partial exits and regime shifts.

Apply the portfolio cap before the new trade. Several individually compliant 0.5% trades can still breach the account drawdown together.

9. Before, during and after-session routine

Before the session

• Read current official rules and change notices.
• Record equity, global threshold, daily cap, reset time and position limit.
• Calculate capacities after buffer and define a personal stop condition.

Before each order

• Recalculate current-day P&L and existing open risk.
• Size from the smallest available cap with realistic execution costs.
• Stress simultaneous losses across correlated positions.

After the session

• Record the reference balance or equity and new trailing threshold.
• Check the effect of payouts, resets and phase changes.
• Archive dated rules and next-session inputs.

10. Common causes of accidental breaches

• Risking a percentage of nominal size without checking the live threshold.
• Ignoring unrealized P&L when the rule monitors real-time equity.
• Using local midnight instead of the provider’s reset time.
• Targeting the exact limit with no execution buffer.
• Forgetting that a trailing threshold rose after a winning day.
• Adding correlated positions as if they were independent.
• Keeping stale inputs after a payout or account transition.
• Relying on a community summary instead of dated official rules.