What return did my DeGiro portfolio actually make?
The obvious way to answer this -- what it's worth now, minus what you've put in -- is also the way most likely to mislead you, and the more deposits you've made, the worse it gets.
The obvious calculation, and why it isn't a return
“I've put in €20,000 and it's worth €23,000, so I'm up 15%” is arithmetic, not a return. A return has to answer a question with a timeframe in it — 15% over what period, earned by which money? — and “everything I've ever deposited” is not a period. It's a pile of deposits made on different dates, each of which has had a different amount of time to grow.
Put €10,000 in on day one and it grows 15% by year end: a plain 15% return, no argument. Add another €10,000 the week before year end and the same €23,000 balance now means something closer to a 30% return on the money that was actually exposed to the market for most of the year — the second €10,000 barely had time to move. Total value minus total deposits can't tell these two years apart, because it never looked at when the money arrived.
Same deposits, same balance, three different years
Three accounts each had €20,000 put in during the year and each is worth €23,000 on 31 December, so “worth now minus put in” says 15% for all three. Here is what actually happened in each.
Account A put the whole €20,000 in on 1 January and left it. The investments gained 15%, and both a time-weighted return and XIRR say 15.0%. This is the one case where the obvious calculation is right: a single deposit at the very start.
Account B put €10,000 in on 1 January. By 30 November it was worth €12,800, a 28% gain. The second €10,000 went in on 1 December, making €22,800, and the month ended at €23,000. The time-weighted return is 1.28 × (23,000 ÷ 22,800) − 1 = 29.1%, and XIRR is 28.0%. The investments roughly doubled what the obvious calculation gives them credit for, because half the money sat in the account for only one month.
Account C also started with €10,000 on 1 January, but it fell to €9,000 by 30 June. The second €10,000 went in on 1 July, making €19,000, and the year ended at €23,000. The time-weighted return is 0.90 × (23,000 ÷ 19,000) − 1 = 8.9%; XIRR is 20.3%. The investments had a mediocre year, but the second deposit happened to land just before the good half, so the money itself did well.
Three different years — 29%, 15% and 9% for the investments — and the obvious calculation can't tell any of them apart. That is the whole case for a real return.
Which money counts as “put in”
Only money that crosses the boundary of the account counts: deposits from your bank and withdrawals back to it. Everything that happens inside the account — buying or selling shares, a dividend landing in cash, a fee, a currency conversion — changes what the account holds but not what you put in. Buying €1,000 of an ETF is not an investment of €1,000 for this purpose: the €1,000 was already in the account, and it has just changed form.
Two slips are common. The first is forgetting withdrawals: if you've taken €3,000 out over the years, what you've put in is your deposits minus that €3,000, and leaving it out makes your result look €3,000 worse than it was. The second is counting dividends as new money. A dividend paid into your cash balance is part of your return, not a deposit — it's the account earning, not you adding.
What a real return has to account for
A return that means something either removes the effect of cash-flow timing (a time-weighted return, TWR) or prices it in on purpose (a money-weighted return, XIRR) — see the TWR vs XIRR guide for what each one actually answers, and a worked example of the two disagreeing on the same account.
Either way the ingredients are the same: every deposit and withdrawal, dated, plus a daily value for the account in between — not just a start and an end balance. Two numbers can't tell a steady year from a lucky, or unlucky, one.
What the export already has
Transactions.csv and Account.csv between them carry every trade, deposit, withdrawal, dividend and fee with its own date — everything a real return calculation asks for. What they don't do is the calculation itself: daily valuation, chain-linking sub-period returns, and solving for a rate for XIRR. That's the part this tracker does with the two files once you upload them, and it's also entirely doable by hand for anyone who'd rather check the arithmetic than trust it — the spreadsheet guide shows how, step by step.