A stop loss is the single most important order you'll place on MetaTrader 5 — it's what caps your loss if the market moves against you. This guide walks you through every way to set one: on the desktop terminal, on the mobile app, on a live trade, and as an automatic default for every order.
Why a Stop Loss Matters More Than Your Entry
Most traders obsess over finding the perfect entry and ignore the exit. That's backwards. Your stop loss defines your risk — the exact dollar amount you can lose — and risk is the only variable you actually control in the market. Without a stop loss, one bad move can wipe out weeks of gains, and on a prop firm challenge, it can breach your daily drawdown instantly.
Here's the mental model: entry, stop loss, and take profit should all be decided before you click buy or sell.
How to Set a Stop Loss When Opening a New Order (Desktop)
- Open the New Order window: press F9, or right-click any chart and choose Trading → New Order, or click the "New Order" button in the toolbar.
- Pick the symbol and volume (lot size) at the top.
- Find the Stop Loss field — it sits next to "Take Profit" in the order window. Click the price field and type your stop loss price.
- Enable the line: make sure the stop loss level isn't greyed out. If the price is on the wrong side of the market, MT5 will show an "Invalid stops" error.
- Click Buy or Sell. Your stop loss is now attached to the position.
How to Add a Stop Loss to an Open Trade (Desktop)
Forgot to set it when you entered? You can add one any time:
- Right-click the position in the Trade tab and select Modify or Delete Order.
- In the window that opens, type your level in the Stop Loss field, then click Modify.
- Even faster: double-click the position in the Trade tab to open the same window directly.
How to Set a Stop Loss on MT5 Mobile (iPhone & Android)
- Tap the Trade tab at the bottom to see your open positions.
- Tap the position you want to edit.
- Tap the pencil (edit) icon, or long-press the position and choose Modify.
- Enter your price in the Stop Loss field and confirm.
On a new order in the mobile app, the order screen shows Stop Loss and Take Profit fields before you execute — fill them in before tapping Buy or Sell.
How to Set a Default Stop Loss on Every Order
Want MT5 to attach a stop loss automatically so you never forget? You can't set a global default in standard MT5, but two workarounds help:
- One-click trading: enable it (Alt+T), and use the quick order panel — it remembers the last stop loss/take profit values you used.
- Expert Advisors (EAs): a small EA can auto-attach a fixed-pip stop loss to every trade. Only use EAs from sources you trust.
Where Should You Place the Stop Loss?
The right location depends on your strategy, but the common-sense rule is to place it where your trade idea is proven wrong — below a recent swing low for a long, above a swing high for a short. Give the market room to breathe, but keep the distance small enough that a single loss doesn't hurt.
For prop firm traders specifically: convert your stop distance into a lot size so a stop-out costs no more than ~1% of the account. That's how you stay alive inside daily drawdown rules.
Common MT5 Stop Loss Errors (and Fixes)
- "Invalid stops": your stop loss is on the wrong side of the current price (below for a buy, above for a sell). Flip it.
- Stop too close: brokers enforce a minimum stop distance. Move it a few pips further from the market.
- Stop loss not showing on the chart: it's attached but hidden — right-click the chart, choose Objects, and make sure Stop Loss levels are visible.
A Worked Example: Stop Loss on a $100,000 Prop Account
Say you're on a $100,000 prop firm challenge and you go long EUR/USD at 1.0850. Your strategy says the trade idea is invalid below the recent swing low at 1.0800, so that's your stop loss — 50 pips away.
Now size the position so a stop-out costs ~1% ($1,000) of the account. If 1 standard lot moves $10 per pip, then 50 pips is $500 per lot. Two lots would be $1,000 — so you trade 2 lots, stop at 1.0800. If the stop hits, you lose exactly your planned 1%, and the daily drawdown is never in danger.
This is the whole discipline in one example: stop distance first, then lot size to match your risk budget.
Common Stop Loss Mistakes That Blow Accounts
- No stop at all — hoping a losing trade "comes back." It's how accounts die.
- Moving the stop wider after the trade goes against you — the classic "just give it more room" spiral.
- Placing the stop at an arbitrary round number instead of where the setup is actually invalid.
- Too much size with a tight stop — a 5-pip stop sounds safe, but with 10 lots it's still a $500 loss.
FAQ: Setting a Stop Loss on MT5
Can I set a stop loss after the trade is already open? Yes — right-click the position in the Trade tab, choose Modify or Delete, and add your level.
Why does MT5 say "Invalid stops"? Your stop is on the wrong side of the current price (below for a buy, above for a sell). Move it to the correct side.
Does a stop loss guarantee my exit price? No — in a fast gap, a stop loss becomes a market order and can fill at a worse price. This is called slippage.
Bottom Line
Setting a stop loss on MT5 takes five seconds and is the difference between a controlled loss and a blown account. Set it when you open the order, size your position so the loss is survivable, and you've already fixed the most common reason traders fail.