Pros and cons of a stop loss order
Like any tool, a stop loss order has clear strengths and limits. You should know both before using one:
Pros of a stop loss order
Limit losses: You define your maximum risk per position before entering.
Fewer emotional decisions: The exit is set in advance, which can reduce decisions driven by fear or greed.
Automation: The position closes automatically without you having to watch the market constantly.
Lock in gains: With a moved-up stop or trailing stop, you protect gains already achieved.
Cons of a stop loss order
No guaranteed price: As a market order, it sells at the next available price, not exactly at the stop level.
Early triggering: A stop set too close can trigger during normal fluctuations and push you out of an otherwise good position.
No protection against price gaps: If the price gaps below the stop level overnight, the sale happens below that level.
Missed recovery: After selling near a low, you may miss a subsequent recovery.
Slippage, gaps and whipsaw: the risks of a stop loss order in detail
A stop loss order does not give absolute protection against losses because it depends on market liquidity and price dynamics. In practice, three built-in risks determine how reliably the protection works during turbulent market phases.
Slippage
Slippage is the difference between your stop level and the actual sale price. Since the triggered sell order enters the market as a market order, it executes at the best available price. You can never remove this risk completely, but you can reduce it by placing orders only on large, liquid trading venues and by paying attention to volatile market phases, such as right after major company results are released.
Gap risk
A gap is a price gap that typically arises overnight or at the weekend when new information causes a sudden price change. A stop loss order does not protect against price gaps. Example: a share closes at 100 euros and your stop is at 90 euros. Overnight, the company issues a profit warning and the share opens the next morning at 70 euros. The order triggers and sells near 70 euros, even though your stop was at 90 euros.
Whipsaw effect
With the whipsaw effect, the market briefly moves against your position, triggers the stop, and then turns back in the original direction. In volatile sideways phases, this can happen several times and lead to a series of small losses. Very tight stops of around 5% are especially vulnerable, while more moderate distances have performed better in multi-year backtests. Past price movements are not an indicator of future results.
Stop loss in a buy-and-hold strategy
Whether a stop loss order makes sense depends heavily on your strategy. For active traders who operate over shorter time frames, it can be a tool for limiting false signals and strong counter-moves. For long-term buy-and-hold investors, the picture is different. If you invest broadly across shares or ETFs for many years, many investors prefer to ride out fluctuations rather than sell. A rigid stop loss order can even hurt in this case because it forces a sale during a temporary correction, and you may miss the recovery that follows.
A stop can still make sense in this context mainly for:
What does a stop loss order cost?
When you place a stop loss order, most providers charge nothing. Fees apply only once the order is triggered and your sale is executed. They are then the normal trading fees your broker charges for a sale. So you do not pay more for a stop loss order than for a normal sale.
A less obvious cost component is the spread between the buy and sell price. In volatile or illiquid markets in particular, the actual sale price can be below your stop level, increasing the realised loss. These indirect costs do not appear as a fee, but they belong in an honest view of total costs.
Margin trading: why leverage requires a stop loss order
In margin trading, the stop loss order is not an optional tool. It is the central instrument for protecting your capital. The reason is leverage: since you deposit only a fraction of the total position value as collateral, or margin, price movements are multiplied. This mechanism increases possible gains, but it accelerates losses to the same degree. With leverage of 1:10, for example, a price move of only 10% against your market direction is enough to wipe out the capital you put in.
If the balance in your margin account falls below a critical threshold, a margin call occurs and the broker automatically closes the position to protect you from uncontrollable losses. A strategically placed stop loss order prevents such extreme scenarios by closing the position systematically and in a controlled way long before the broker’s forced liquidation has to take effect.
Even with this essential protective function, remember that gap risk and slippage risk remain in margin trading during extreme market jumps or sudden liquidity shortages. Execution at the exact desired price cannot be guaranteed here either.