A stop-loss order sets an exit instruction before a spread bet moves further against you. It does not necessarily set the price at which that exit happens. That distinction separates an ordinary stop from a guaranteed stop, and it still matters when a trailing stop has moved into profit.
In financial spread betting, the cash result depends on your stake per point and the distance between your opening and closing prices. Choosing a stop therefore means making three decisions: where the trade should end, how much money that distance represents, and whether you need protection against execution beyond your chosen level.
How an Ordinary Stop-Loss Order Works
A protective stop on a long position sits below the current market price and instructs the provider to sell to close. On a short position, it sits above the market and instructs the provider to buy back. A stop can reduce an existing loss or protect part of an unrealised profit.
The stop level is a trigger, not a guaranteed execution price. Once triggered, an ordinary stop seeks execution at an available price under the provider’s terms. A fast move can produce a worse result, known as adverse slippage. The same trigger-versus-execution distinction applies to securities orders, covered in FINRA’s warning about stop orders during volatile markets; spread betting execution depends on the contract with your provider.
A Stop-Loss Calculation in Pounds per Point
Suppose you open a long index spread bet at 8,000 for £2 per point and place a stop at 7,950. Your intended price loss is:
50 points × £2 per point = £100.
If the position closes at 7,950, that is the loss before separate charges. If prices gap lower and the execution price is 7,920, the loss becomes 80 points × £2, or £160.
Both outcomes are consistent with an ordinary stop. The instruction may work as intended while the eventual loss exceeds the planning figure. “Stop-loss” is an order name, not a promise about the final bill.
These examples use actual opening and closing dealing prices, so their difference already reflects the spread. Do not add the spread a second time. Financing and any separate fees remain outside the calculation.
Standard, Guaranteed and Trailing Stops Compared
The three labels describe different features. An ordinary stop provides an exit trigger. A guaranteed stop adds contractual protection for the execution level. A trailing stop changes the trigger as the market moves favourably. Automatic movement does not itself provide a price guarantee.
| Stop type | How the level behaves | Execution protection | Main consideration |
|---|---|---|---|
| Ordinary stop | Stays at the chosen level unless amended | Can execute beyond the stop level | The planned loss can be exceeded |
| Guaranteed stop | Uses an agreed level under the provider’s terms | Protects the agreed stop execution level | Check charges, availability and restrictions |
| Trailing stop | Moves with favourable prices but does not retreat automatically | Usually remains subject to slippage unless expressly guaranteed | A tight trail can trigger during a temporary reversal |
What a Guaranteed Stop Actually Guarantees
A guaranteed stop-loss order is a contractual commitment to close a covered position at the agreed stop level even if the market gaps through it, subject to the accepted terms. It protects the exit price, not the profitability of the trade. The distinction between ordinary and guaranteed stops, including the need to check the agreement, appears in ASIC’s CFD risk guide, in its section on stop losses.
Return to the £2-per-point position opened at 8,000. With an accepted guaranteed stop at 7,950, the covered price loss is £100 even if the market next quotes 7,920. Any applicable guarantee premium, financing or other charge must still be counted.
Include the Premium in the Risk Budget
Consider a hypothetical guarantee premium of three points, payable if the stop triggers. At £2 per point, that adds £6. The stopped trade would therefore cost £106 before financing or other adjustments, rather than £100. This is an illustration, not a quoted market rate.
Before using a guarantee, establish when the premium becomes payable, whether it is refundable, and whether changing the position changes the charge. Also check the minimum permitted stop distance, covered markets and restrictions on amendments. Do not assume a stop becomes guaranteed simply because you selected a price in the order ticket.
A guarantee is most relevant to your decision when the difference between planned and possible execution would make the trade unacceptable. Compare its terms with alternatives such as reducing the stake, closing before an event or not opening the position. The wider treatment of premiums and holding charges belongs in your spread betting cost calculation.
How Trailing Stops Follow a Profitable Move
A trailing stop adjusts its trigger when the market moves in your favour. For a long position, it moves upwards; for a short position, it moves downwards. When the market reverses, the trigger stays put rather than moving away again. This mechanism is covered in the SEC investor bulletin on trailing stop orders, although the settings available on a spread betting platform depend on its provider.
Suppose a long index trade opens at 8,000 with a 40-point trailing distance. Assume the relevant trigger quote is also 8,000 when trailing starts, and the stop follows each favourable move:
- The initial stop sits at 7,960.
- The quote rises to 8,030, lifting the stop to 7,990.
- The quote reaches 8,100, lifting the stop to 8,060.
- The quote falls to 8,080, but the stop remains at 8,060.
If the stop later executes at 8,060, the trade gains 60 points. At £2 per point, that is £120 before separate charges. An ordinary trailing stop could execute lower, so the displayed stop level is not a guaranteed minimum profit.
Trailing Distance and Trailing Step Are Different
Where a platform offers both settings, the trailing distance defines the gap behind the favourable price. The trailing step defines how much further the market must move before the stop updates. Check the platform’s definition rather than assuming every small price change moves the stop.
A narrow trail gives back less of an unrealised gain before triggering, but allows less room for a temporary reversal. A wider trail permits a larger retreat. Neither setting can identify in advance whether the next pullback is harmless or the start of a sustained move against you.
For comparison, test several distances against the same entry rules and record both the profit retained and the trades ended prematurely. Do not choose a setting solely because it would have captured one memorable rally.
Why a Stop Can Trigger When the Chart Looks Untouched
A spread betting quote has two sides. A long position closes at the provider’s selling price, or bid. A short position closes at its buying price, or offer. A chart showing a midpoint or a different price feed may not display the quote relevant to your stop.
Consider a short position with a stop at 8,050. A hypothetical quote widens to 8,030–8,052. The midpoint is 8,041, below the stop, but the offer is already above it. If the provider uses that offer to trigger the short position’s stop, the order can activate without the midpoint chart reaching 8,050.
Before questioning an execution, compare the order confirmation, trigger rules, relevant quote and timestamp. Ask for the pricing record if the explanation remains unclear. A chart screenshot alone may not establish whether the stop should have triggered.
A Stop-Limit Order Is Not a Guaranteed Stop
Where available, a stop-limit order activates a limit order rather than an unrestricted market exit. It controls the acceptable execution price but introduces the possibility of no execution. That trade-off is addressed in FINRA’s guidance on stop and stop-limit risks.
For example, a sell stop-limit with a trigger at 7,950 and a limit at 7,940 will not authorise a sale below 7,940. If available prices jump to 7,920, the position may remain open. Preventing an unacceptable fill is not the same as preventing a larger loss.
Match the Stake to the Stop Distance
Choose an exit level that fits the trading idea, then calculate whether the corresponding stake fits your budget. Moving the stop closer simply to make a large position look affordable changes the trade rather than removing its risk.
Indicative stake per point = price-loss budget ÷ stop distance in points.
With a £120 price-loss budget and a 60-point stop distance, the indicative stake is £2 per point. If the intended exit needs to be 100 points away, the equivalent stake falls to £1.20 per point. These figures exclude charges and, for an ordinary stop, any slippage.
If £120 is the entire cash budget, reserve room for costs before calculating the stake. An assumed slippage allowance is only a planning input, not a ceiling. The broader process is covered in position sizing and setting a trading risk budget.
Moving the stop further away after entry also changes the cash exposure. At £2 per point, widening a stop from 50 to 90 points increases the intended price loss from £100 to £180. Calling this “giving the trade room” does not change the arithmetic.
Likewise, moving a stop to the opening price does not necessarily create a true break-even trade. Separate charges can leave a net loss, and an ordinary stop can slip beyond that level.
Stops Do Not Replace Account-Level Protection
For UK retail accounts within the relevant rules, negative balance protection caps liability for covered speculative investments at the funds in the account. It does not cap each trade at its chosen stop. The FCA’s COBS 22.5 rules also require firms to close positions as soon as market conditions allow when account net equity falls below 50% of the required margin.
This creates three separate controls: your chosen stop, the account’s margin close-out mechanism and negative balance protection. They address different risks. A £100 planned stop loss is not protected simply because the account has negative balance protection.
It also follows that account-level margin pressure can cause a position to close before its stop is reached. A guaranteed stop is not a promise that the position will remain open until that level. Assess the whole account rather than treating each order in isolation.
For example, three hypothetical positions with intended losses of £100 each represent £300 of planned price exposure before costs or adverse execution. If all three depend on the same market move, they could be stopped together. Review that exposure alongside the account’s margin requirements and close-out rules.
Check the Order Before Relying on It
Before placing a trade, confirm the stop type, trigger price, stake, covered position size and any premium. Check whether the order remains active outside normal market hours and whether trailing operates on the provider’s servers or requires your trading software to stay connected. Treat these as questions for the actual platform, not assumptions carried over from another account.
After submission, verify that the provider accepted the stop and that it appears against the intended position. Repeat that check after changing the stake or partially closing the trade. A price typed into a ticket is not the same as a confirmed instruction.
Choose an ordinary stop with an explicit allowance for uncertain execution, a guaranteed stop when contractual price protection is needed, and a trailing stop when the exit should adjust with favourable movement. None repairs an oversized position. The stop and the stake must make sense together before the trade begins.