Why is my realised profit different from the unrealised profit I saw before selling?
Your realised profit is usually different from the unrealised profit you saw before selling because the portfolio estimates unrealised profit using the mid price, while realised profit is based on the price your sale actually executed at. The mid price is the midpoint between the bid and the ask. A sell order trades against the bid side, which is normally lower, so the realised figure tends to come in slightly below the estimate. The gap can grow because of slippage: the execution price depends on order book depth, market volatility and how far the price moves between the moment you check your portfolio and the moment your order fills. Fees on the sale also make the amount you receive differ from the estimate. A market order fills at the best price available at that moment, which makes it more exposed to slippage; a limit order, where it is available, lets you set the minimum price you are willing to sell at, although it may not fill.
Unrealised and realised, side by side
| Unrealised profit (before selling) | Realised profit (after selling) | |
|---|---|---|
| Price used | Mid price, between bid and ask | The price your sell order actually filled at |
| Status | An estimate that moves with the market | Settled, and no longer moves |
| Affected by | Price movement while you hold | The bid side, slippage, and fees on the sale |
Worked example (fees left out to keep it simple)
You bought 1 US stock at an average of US$90. Before selling, the mid price is US$100, so the portfolio shows US$10 unrealised profit. Your sell order fills at US$99.80, on the bid side.
- Unrealised profit before selling: US$100 − US$90 = US$10
- Realised profit after selling: US$99.80 − US$90 = US$9.80
What drives slippage
- Order book depth. If there aren't enough buyers at the best bid for the amount you're selling, part of the order fills at lower bids.
- Volatility. In a fast-moving market, the price can change between placing an order and its execution.
- Timing. Quiet trading periods have fewer offers close to the current price, so executions can land further from the mid price.
Related questions:
Q: What is slippage?
Slippage is the difference between the price you expected when you placed an order and the price the order actually executed at. It happens because prices keep moving and because the best available price only covers a limited amount. Slippage can work against you or in your favour, but for a market order in a fast or thin market it more often works against you. It is one of the main reasons realised profit differs from the unrealised figure you saw.
Q: How can I reduce slippage when selling?
A limit order is the most direct tool where it is available: you set the minimum price you are willing to accept, and the order fills only at that price or better. The trade-off is that it may fill only in part, or not at all, if the market doesn't reach your price. Selling in smaller amounts and avoiding very quiet or very volatile moments can also help. None of these guarantee a particular price.
Q: Can my realised profit be higher than the unrealised profit I saw?
Yes. If the price rises between the moment you check your portfolio and the moment your sell order fills, you can realise more than the unrealised figure you saw. Slippage is not always negative; it simply reflects price movement during execution. In most cases, though, the realised figure comes in slightly lower, because the sell order trades against the bid side, which sits below the mid price used for the estimate.
Q: Does the unrealised profit in my portfolio include selling costs?
No. Unrealised profit is an estimate at the mid price, so it doesn't account for the spread you cross when you sell, or for the fees on the sale. That is intentional: it shows how your holding is valued by the market right now, not what a particular sale would bring. To see what a sale would actually cost you, check the sell price and fee breakdown shown before you confirm the order.