Trailing drawdown is the single rule that closes more prop-firm accounts than any other — and most traders only learn how it actually works after it closes theirs. Here's the mechanic-level explainer: the two flavors, the lock point, and why six major firms each implement it slightly differently.
A trailing drawdown is a moving floor underneath your account. It starts a fixed distance below the account's starting balance — say, $3,000 below a 100K account, putting the floor at $97,000. As your account grows, the floor moves up behind it. When your account shrinks, the floor stays where it is. Touch the floor with your balance, and the account closes — no warning, no second chance, no "are you sure."
The reason most blown funded accounts die to this rule isn't that traders don't know trailing drawdown exists. It's that they don't track where it currently sits. The floor at the start of today's session is rarely the floor at the start of yesterday's. After a strong session, it's higher. After a clean run of profitable days, it can sit dangerously close to your live balance — close enough that a normal-sized losing trade now becomes account-ending.
Every firm running a trailing drawdown picks one of two implementations. The headline number can look identical — "$3,000 trail on a 100K account" — but the trigger timing is completely different.
Intraday HWM is the harsher mechanic for traders who let trades run; EOD is harsher for traders who give back winners into the close. Neither is "better" in absolute terms — they reward different trading styles. The Apex 4.0 EOD vs Intraday deep dive walks the exact same-trade comparison for the one firm that lets you choose.
The floor doesn't trail forever. At a firm-specific threshold, it freezes — usually at or near the starting balance — and never moves again. The lock is where you finally earn a stable buffer that doesn't shrink with every winning session. There are two conventions in 2026, and which one your firm uses changes the math significantly.
| Lock convention | What it means | Used by |
|---|---|---|
| Starting balance (SB) | Floor locks exactly at the account's original starting balance. On a 100K account, the floor freezes at $100,000. | Topstep, TPT, Earn2Trade |
| SB + $100 | Floor locks $100 above the starting balance — a small "safety net" added by the 4.0-era SB+$100 family of firms. On a 100K account, the floor freezes at $103,100 (after rising $3,100 above SB). | Apex 4.0, MFFU, Tradeify, Bulenox |
Same trader, same Combine size (100K), same winning week of +$1,800 closed P&L spread across five sessions. Two different firms with two different trail-DD conventions: Topstep (intraday HWM, SB lock) and Apex 4.0 EOD (EOD trail, SB+$100 lock).
End of week: same trader, same closed P&L, but Topstep's floor has rocketed up 2,300 because of the intraday wicks and has already locked at SB — meaning the trader has a real stable buffer. Apex 4.0 EOD's floor has only moved $1,800 (matching the actual close P&L) and still has ~$4,300 to go before locking at $103,100. The Apex trader has more current buffer-to-floor headroom; the Topstep trader has an earlier locked floor that no future wick can move.
For any account on any firm, the live trail-DD floor at any moment is:
Two practical consequences:
The six largest US prop firms in 2026, side-by-side, on the two questions that matter — flavor and lock point. All numbers are for the most popular Combine / eval size (100K) at publish time; verify with your firm before sizing.
| Firm | Trail flavor | Lock point | Locked buffer (100K) |
|---|---|---|---|
| Topstep | Intraday HWM | SB ($100,000) | $3,000 |
| Apex 4.0 Intraday | Intraday HWM | SB + $100 ($103,100) | $3,100 |
| Apex 4.0 EOD | EOD | SB + $100 ($103,100) | $3,100 |
| MyFundedFutures | Intraday HWM | SB + $100 ($103,100) | $3,100 |
| TPT (Test/PRO/PRO+) | Phase-shifts (EOD → Intraday → EOD) | SB ($100,000) | $2,500 |
| Tradeify Growth | EOD | SB + $100 ($103,100) | $3,100 |
| Bulenox Option 1 / 2 | Choice: Intraday or EOD | SB + $100 ($103,100) | $3,000 |
| Earn2Trade GAU | EOD | SB ($100,000) | $3,500 |
Two structural patterns in this table worth seeing:
The headline drawdown number on your firm's marketing page is the starting DD. After three winning sessions, your real floor is somewhere else — and you can't see it from the broker's UI. These tools run in your browser, no login, no card:
Topstep, Apex 4.0 (EOD + Intraday), MFFU, TPT, Tradeify, Bulenox, Earn2Trade presets. Enter your closed P&L history → see your real current floor, headroom, and distance-to-lock.
Open the calculator →Stop in ticks → max contracts, % of trail-DD buffer used per trade, N losses to floor. Same firm presets as the trail calc; pairs naturally.
Open the calculator →Aurafy reads your broker's CSV or Rithmic statement, computes the live trail-DD floor for each account against the correct firm preset (Topstep, Apex 4.0 EOD or Intraday, MFFU, TPT phase-shift-aware, Tradeify, Bulenox, Earn2Trade), and shows you the headroom before you size the next trade. Same tool also covers consistency-rule thresholds, daily loss limits where applicable, and the screen recording the brokers don't ship. Free tier never expires (last 30 days, 1 account, 3 playbooks, no card). First 50 founders: $19/mo locked for life.
Start free — no card See $19 founder seatDepends on the firm. On most SB-family firms (Topstep, Earn2Trade), the trail continues into the funded account and locks at the starting balance. On SB+$100 firms (Apex 4.0, MFFU, Tradeify, Bulenox), the trail continues until the lock at SB + $100. TPT shifts the trail mechanic across Test → PRO → PRO+ phases (EOD → Intraday → EOD), keeping the same SB lock. The eval is not the lock event — passing the eval just transitions you into the funded version of the same rule.
For firms running intraday HWM trail (Topstep, Apex 4.0 Intraday, MFFU, Bulenox Option 1), yes — the floor tracks the highest balance including open positions. A wick to +$1,200 unrealized on a position you closed at +$300 counts as +$1,200 for floor-movement purposes. For EOD-trail firms (Apex 4.0 EOD, Tradeify Growth, Bulenox Option 2, Earn2Trade), unrealized P&L is ignored — only the closed daily balance moves the floor.
The trailing drawdown is account-life: one floor, moves up with profits, never moves back down, locks at SB or SB+$100, hitting it closes the account. A daily loss limit (DLL) is session-life: resets every trading day, hitting it ends today's session but doesn't close the account. Some firms run both (Topstep enforces DLL on NinjaTrader but removed it on TopstepX in 2024); some run trail only (Apex 4.0, MFFU); some run neither (MFFU on funded). Track them as two separate floors with two separate consequences. Topstep vs MFFU walks the DLL contrast in detail.
No. Lock is permanent. Once your floor reaches SB or SB+$100 (depending on firm), it freezes there. A subsequent losing run that takes your balance below the locked floor closes the account — but the floor doesn't move down. The lock is your reward for the climb; account closure is the only event that ends the rule's life.
Trail does not reset on add/withdrawal in general — the floor reference is the starting balance set at purchase. Payouts are deducted from your live balance but do not change the floor's mathematical position. This is the rule that makes consistency-rule + payout-eligibility tracking non-trivial: a payout doesn't give you a fresh DD buffer; it shrinks the buffer above the existing floor. Plan payouts after the trail has locked, not during the climb.
The marketing page shows the starting DD (the gap at purchase between SB and the initial floor — e.g. "$3,000 trailing drawdown on 100K"). Your calculator's floor is the current floor after every closed session's movement. After three winning days, those are two different numbers. The marketing number is the starting condition; the calculator number is the live state. Always track live state for sizing decisions, not the starting condition.