Intraday Drawdown Math: Real Examples of How Your Floor Moves and When You're in Danger

Intraday trailing drawdown moves your floor in real time based on your equity peak — including unrealized profits on open positions. This is what makes it more demanding than EOD drawdown: you can breach the floor on a trade that starts well and reverses, even if you end the session flat or slightly positive on a closed-trade basis.

The math isn't complicated. But most traders haven't worked through it explicitly, which means they discover the rules at the worst possible moment.

The Basic Mechanic

With intraday trailing drawdown:

• Your drawdown floor starts at: starting balance − maximum drawdown allowance
• As your equity rises (either from realized gains or unrealized gains on open positions), the floor moves up to maintain the same dollar distance
• The floor never moves down — it only trails upward
• If your equity (including open position P&L) touches the floor at any point during the session, your account is in violation

Example 1: Quiet Day, No Open Positions

Account: $100K starting balance. Apex PA ($3,000 max trailing drawdown).
Starting floor: $100,000 − $3,000 = $97,000

You make three small trades, net +$400. You close each trade before opening the next.

After trade 1 (+$200): Equity peak = $100,200. Floor moves to $100,200 − $3,000 = $97,200.
After trade 2 (+$150): Equity peak = $100,350. Floor = $97,350.
After trade 3 (+$50): Equity peak = $100,400. Floor = $97,400.

Current equity: $100,400. Distance to floor: $3,000. Nothing concerning.

Example 2: The Dangerous Scenario — Open Position Reversal

Same account. $100K starting, $97,000 floor. You've made $1,500 already. Current equity: $101,500. Current floor: $98,500.

You enter a long NQ trade. The trade goes immediately in your favor — up $1,200 in open profit. Your unrealized equity is now $102,700. Floor moves to $99,700.

The trade reverses. Fast. Down $2,200 from the entry point. Current open P&L: −$1,000. Current equity (including open position): $101,500 − $1,000 = $100,500.

Are you safe? Floor is $99,700. Current equity is $100,500. You have $800 of cushion.

The trade keeps going against you. Down another $800. Equity: $99,700. You're at the floor — violation.

Key insight: You entered the trade with $3,000 of cushion. But the trade moved in your favor first, pulling the floor up by $1,200. That $1,200 of "good" price action reduced your actual risk buffer from $3,000 to $1,800 before the reversal started. You had less room than you thought.

Example 3: Calculating True Cushion on Open Positions

To know your actual risk buffer on an open position under intraday trailing drawdown:

True cushion = Current equity − Current floor

Where current equity includes the open position's current P&L. This number changes every tick. The maximum adverse move your open position can take before breaching the floor is exactly your current cushion.

In the example above: after the trade moved +$1,200 in your favor, true cushion = $102,700 − $99,700 = $3,000. But wait — the floor also moved up. True cushion stayed at $3,000? Not quite: the floor moved up by the same amount as the equity gain, so the distance was maintained. But the reversal from the peak, not from your entry, is what matters.

When the trade peaks at +$1,200 and then reverses to −$1,000 from entry, the reversal from the peak is $2,200. Your true cushion at the peak was $3,000. A $2,200 reversal from the peak leaves $800 of cushion — which is what we calculated.

The practical rule: Your maximum trade reversal tolerance (from the intraday equity peak, not from entry) equals your true cushion at the peak. If the trade peaked at $1,200 open profit and you had $3,000 cushion at that peak, the trade can reverse up to $3,000 from the $1,200 peak before breaching the floor — meaning it can go $1,800 against you from entry before you hit the floor.

Automating This in Real Time

Tracking true cushion manually while managing a live trade is impractical. Copilink's intraday drawdown monitoring tracks current equity (including open positions) against the current floor in real time, updating every tick. Alert thresholds at 70% and 85% of the maximum drawdown notify you before you're in danger — not after the floor is breached. Start at copilink.com.