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You switch your cost basis from FIFO to LIFO and your Wednesday drops from +$500 to +$300, while the trade itself still shows the same total. Nothing is wrong with your data: the method only decides which purchase each sale is matched against, so it moves profit from one day to another. It never changes what a closed trade made in total.
Why it happens
To know the profit of a sale, TraderSync has to match it to a purchase. Only your sales carry profit; the purchases themselves show $0. You choose the matching method in Settings > Trades > Cost Basis Calculation:
- FIFO (the default): each sale is matched against your oldest purchase first.
- LIFO: each sale is matched against your newest purchase first.
- Weighted Average: every sale uses the average price of the trade’s purchases.
An example
You buy 100 shares on Monday at $10 and 100 on Tuesday at $12. You sell 100 on Wednesday at $15 and 100 on Thursday at $14. The trade made +$700 in total (illustrative, gross, no fees). Here is how each method splits it between your two sales:
| Method | Wednesday sale | Thursday sale | Trade total |
|---|---|---|---|
| FIFO | +$500 (against Monday’s $10) | +$200 (against Tuesday’s $12) | +$700 |
| LIFO | +$300 (against Tuesday’s $12) | +$400 (against Monday’s $10) | +$700 |
| Weighted Average | +$400 (against the $11 average) | +$300 (against the $11 average) | +$700 |
So the $200 that leaves Wednesday when you switch from FIFO to LIFO shows up on Thursday. Two things to know:
- You only see the days move when your reports use Transaction Date. With Open Date, all +$700 counts on Monday; with Close Date (the default), all of it counts on Thursday. In both cases changing the cost basis moves nothing.
- Weighted Average uses all of the trade’s purchases, including ones made after a sale. Buy 100 at $10 on Monday, sell 50 at $12 on Tuesday, buy 100 at $13 on Wednesday, then sell 150 at $14 on Thursday: the average is $11.50, so Tuesday’s sale books +$25 under Weighted Average but +$100 under FIFO. The trade still totals +$400 either way.
What to do
- You want your daily numbers to follow the purchases you sold first: choose FIFO. LIFO follows the most recent purchases, and Weighted Average smooths the two.
- You want the day totals not to depend on the method at all: use Open Date or Close Date for your reports, where each trade counts once, on one day.
To change the method, follow How can I change the partial return calculation between LIFO, FIFO or weighted average? Your choice saves as soon as you pick it, and TraderSync recalculates your trades.
