Prop Shield: loss limits for prop firm challenges
Kalibre Engine checks your Maximum Daily Loss and Maximum Loss on every tick. It blocks new trades near the limit and closes its own positions at the safety margin.
How Prop Shield works
- Daily and total floors. The daily floor is based on the start-of-day balance. The total floor is based on the starting or peak balance. The higher floor applies. The day resets at the firm's time, which is 00:00 CE(S)T for FTMO.
- Lot sizing. The loss of a new trade at its stop, plus the open risk to the stops of existing positions, cannot exceed the distance to the floor. Positions you opened manually are included.
- Stop, then close. At twice the safety margin from the floor, no new trades are opened. At one safety margin, Kalibre Engine closes its own positions and opens no trades until the day resets.
- News rule. If the firm restricts trading around high-impact news, no new trades are opened in that window.
Presets
| Program | Daily loss | Total loss | Source |
|---|---|---|---|
| FTMO 2-Step | 5% | 10%, static | Firm's page, 23 Oct 2026 |
| FTMO 1-Step | 3% | 10%, trails the end-of-day balance peak | Firm's page, 23 Oct 2026 |
| FTMO Instant | 3% | 10%, trails the balance peak intraday | Firm's page, 23 Oct 2026 |
| The5ers High Stakes | 5% | 10% | Firm's page, 23 Oct 2026; cautious setting because the page does not say how the daily limit is calculated |
| Custom | At another firm? Enter your own limits. | ||
Firm rules can change. Compare the preset with your account's terms before you turn Prop Shield on. Consistency rules such as "best day" are not covered.
Check your own account
This calculator runs the same calculation as Prop Shield for one moment. The values stay in your browser.
| Daily floor | |
|---|---|
| Total loss floor | |
| Floor in force | |
| Distance to floor | |
| Largest risk a new trade can carry |
Strategy Tester example
Test setup: a deliberately high-risk strategy in MT5 Strategy Tester. EURUSD M15, 1 January to 1 October 2026, $100,000 starting balance, 5% of balance risked per trade.
| Without Prop Shield | With Prop Shield (FTMO 2-Step) | |
|---|---|---|
| Worst day's realised loss | 18,900 | 4,009 |
| Daily limit (5,000) breached? | Yes, the challenge would be lost | No |
| Lowest balance (total floor 90,000) | 94,432 | 90,999 |
Historical simulation. Hypothetical results have inherent limitations and do not represent actual trading. The account with Prop Shield ended the period at a loss and breached no limit. Prop Shield limits losses. It does not improve a strategy.
Scope and limits
- Prop Shield is part of Kalibre Engine. Kalibre Engine runs the rule file you build in Kalibre Lab on your account. Kalibre does not sell signals.
- Kalibre is not a prop firm and is not affiliated with any prop firm. Firm names are used only to describe their rules.
- Slippage and gaps can cause losses beyond the stop. The safety margin is there for this.
- Prop Shield is in beta and is not a guarantee. Read the risk disclosure before using it on a live account.