Profit and Loss (PnL): What It Means in Simple Terms

PnL (Profit and Loss) is the financial result: the profit and loss on a trade, a day, or an entire trading system. Put simply, it is what actually remains in the account after all entries and exits, accounting for wins and losses. PnL is a basic metric, but calculating it correctly (in money and net of costs) matters more than it seems.

What PnL is

PnL shows the net result of trading. It can be realized (on closed trades) or unrealized (the floating result on open positions). For example, if a trader earned 200 dollars on one trade and lost 80 on another, their realized PnL is +120 dollars before accounting for additional costs. PnL is the bottom-line picture: not how many trades you won, but how much money you actually earned or lost.

Why to count in money, not in trades

The key point: PnL is counted in money and by the bottom line, not by the number of winning trades. Beginners often look only at the count of profitable trades (the win rate), but that is deceptive: a dozen small wins can be overwhelmed by a single large loss. PnL is exactly what shows the bottom-line picture in money, combining both the frequency and the size of trades. A high win rate with a negative PnL is a common situation, where rare large losses eat up frequent small profits.

Accounting for costs

Real PnL must be counted net of all costs: spread, commission, and swap. Profit on the chart and actual PnL often diverge precisely because of costs. A trade that looks profitable by the price move can, after deducting spread and commission, end up flat or in the red, especially on short targets. So PnL should be counted under real conditions, not just by the difference in quotes. Ignoring costs leads to an overstated assessment of the result.

PnL as feedback

PnL is the main indicator of whether a strategy works. But it should be assessed over a distance, not on individual trades: PnL for a day or a week can be random, what matters is PnL over a large series. It is useful to keep PnL in a journal, broken down by strategy, instrument, and time, this shows what actually brings profit and what drags you down. PnL together with other metrics (drawdown, win rate, distribution) gives a full picture of effectiveness.

Practical takeaways

PnL (Profit and Loss) is the net financial result of trading, what actually remains in the account. Count PnL in money and by the bottom line, not by the number of winning trades: a high win rate with a negative PnL happens often. Be sure to account for costs (spread, commission, swap), profit on the chart and real PnL diverge precisely because of them. Assess PnL over a distance rather than on individual trades, and break it down in a journal by strategy and instrument for feedback. Understanding PnL as the bottom-line money result net of costs is the foundation of an honest assessment of trading: without it you cannot tell whether a strategy works or only seems profitable.

This material is for educational purposes and is not individual investment advice.