What is trailing drawdown in prop firms?

What this page is for

If you've ever failed a funded-account challenge and thought "but I was up on the day, how did I blow it?", trailing drawdown is usually the answer. This page explains what the rule is, the two versions firms use, and shows exactly how a profitable-looking account can still breach. Once it clicks you can model it yourself on the trailing drawdown calculator.

How it works (the formula)

A trailing maximum drawdown tracks the highest equity your account has reached and draws a loss line a fixed distance below it:

The key property is that the line is a one-way ratchet. Reach a new equity high and the line steps up with you. Give profit back and the line stays put — it does not follow you down. Two design choices decide how brutal it is:

• Intraday-peak vs end-of-day trailing. An intraday version tracks the highest equity your account touches during the day, including open, unrealized profit. An end-of-day version only records your closing balance, so a spike you didn't lock in never lifts the line.
• Whether it locks. Many programs freeze the trailing line once it climbs up to your original starting balance. After that it behaves like a fixed floor at the start balance and stops trailing. Others never lock and trail all the way up.

Inputs and assumptions

To reason about a trailing drawdown you need four things, all set by your program, not by us:

• Starting balance (e.g. $50,000).
• Drawdown allowance, as a dollar amount or a percent of the start balance.
• Whether it trails the intraday equity peak or only end-of-day balances.
• Whether it locks at the starting balance once it gets there.

The examples below assume the line trails equity (not just closed balance) unless stated, and that no lock has kicked in yet.

Worked example 1 — the normal case

Account starts at $50,000 with a $2,000 (4%) trailing drawdown.

• Opening loss line: $50,000 − $2,000 = $48,000.
• You trade well and equity peaks at $51,500. The line ratchets up to $51,500 − $2,000 = $49,500 — now above your starting balance.
• You give some back and sit at $50,200. That's still above $49,500, so you're fine. Your remaining buffer is $50,200 − $49,500 = $700.

Notice what happened: after making $1,500 of profit, your room to lose is no longer $2,000 from the top — it's $700 from where you are, because the floor kept $1,500 of your gains.

Worked example 2 — breaching while still in profit

Same account: $50,000 start, $2,000 allowance, but this time the rule trails the intraday equity peak.

• You open a trade that runs to +$2,800 unrealized. Equity touches $52,800 intraday, so the line jumps to $52,800 − $2,000 = $50,800 — the floor is now above your $50,000 starting balance.
• The trade gives most of it back and you close with +$1,200 locked in. Balance is $51,200 — a profitable account by any normal reading. But the line stayed at $50,800, so your buffer is only $51,200 − $50,800 = $400.
• A perfectly ordinary $500 loss on the next trade drops equity to $50,700, which is below $50,800. Breached — with the account sitting $700 above the $50,000 you started with, and $1,200 of realized profit on the books.

Under an end-of-day version the story is different: the intraday spike to $52,800 never counts, so while the day is still running the line sits where the prior day's close left it — $48,000 here — and the $500 loss to $50,700 is a non-event. Same account, same trades, opposite outcome — which is why reading this one detail in your rules matters so much.

Common mistakes

• Thinking the line drops back when you give profit back. It doesn't. It's a ratchet; only new highs move it, and only upward.
• Forgetting that unrealized profit can count. Under intraday trailing, a spike you never closed still lifts your floor.
• "I'm still up on the day, so I'm safe." Being above your start balance says nothing once the line has trailed above it.
• Not knowing whether it locks. A program that locks at the start balance is far more forgiving than one that trails forever — treat them as different games.

Methodology & limitations

The definitions and formulas on this page are standard, widely used ways to describe these concepts; every worked-example number is computed by hand from the formula shown so you can reproduce it. Where a rule varies by provider (prop-firm limits especially), we say so — treat the specifics as illustrative, not as any one firm's rulebook.

Not financial advice. This page explains a concept for education only. It is not investment, trading, or financial advice, and no example is a recommendation. Every prop firm writes its own rules and changes them — always verify against your own program, broker, or account terms before acting.

Last updated 2026-07-06.