Understand a portfolio
Contribution or investment profit? How a portfolio really grows
A higher portfolio value does not automatically mean an investment has made a profit. Only by separating contributions, withdrawals and current performance can you see where the wealth really came from.
- Editorial team
- Generavio editorial team
- Published
- Updated
- Reading time
- About 7 minutes
The essential distinction
A contribution brings money into the portfolio from outside. It increases wealth, but it is not investment profit. If you contribute €100 and the portfolio is then worth €100, the investment result is €0. The entire €100 came from your contribution.
This distinction matters when learning as a family: it shows that wealth can change through a family's own saving as well as through positive or negative market movements.
Buying an ETF moves wealth
Suppose the portfolio holds €100 in cash. A simulated ETF purchase uses €40. Afterwards, €60 remains as cash and the ETF shares initially have a value of €40.
Total wealth remains €100 immediately after the purchase. The purchase converted cash into another asset. It created neither a new contribution nor a profit.
- Cash: €60
- ETF value immediately after the purchase: €40
- Total wealth: €100
- Net contributions: €100
- Investment result: €0
Performance changes the investment result
If the ETF position later rises from €40 to €50, total wealth changes. Cash remains €60 while the ETF shares are now worth €50, producing total wealth of €110.
Because €100 has still been contributed from outside, the investment result is +€10. Here it describes the change caused by market performance, not the size of the contribution.
- Cash: €60
- ETF value: €50
- Total wealth: €110
- Net contributions: €100
- Investment result: +€10
What a withdrawal changes
If €20 of cash is then withdrawn, both current total wealth and net contributions fall by €20. The portfolio contains €40 cash and €50 of ETF value, making €90 of total wealth. Net contributions are now €80.
The investment result remains +€10: €90 total wealth minus €80 net contributions. Withdrawing contributed money does not retroactively turn the earlier performance into a loss.
- Cash after the withdrawal: €40
- ETF value: €50
- Total wealth: €90
- Net contributions: €80
- Investment result: still +€10
The two formulas
Net contributions are all contributions minus all withdrawals. The investment result is current total wealth minus those net contributions.
A negative result is possible. If a portfolio with €100 of net contributions is worth €92, its investment result is −€8. That is a factual snapshot of performance, not a forecast of what its value will do next.
- Net contributions = contributions − withdrawals
- Investment result = total wealth − net contributions
Where did your portfolio growth come from?
Enter three values. The calculation happens only in your browser and is not stored.
How the result is composed
Net contributions: €800.00. Investment result: €150.00, positive. Current total wealth: €950.00.
How to explore this with a child
Start with three questions: How much money came in from outside? How much was withdrawn? What is the whole portfolio worth today? The calculator on this page then shows how much is explained by net contributions and how much by performance.
The aim is not to judge every daily price movement. What matters is understanding that saving, investing and market movements are different events.
Frequently asked questions
Is a contribution a profit?
No. A contribution increases portfolio wealth, but it comes from the contributor. It counts towards contributions, not the investment result.
Why does buying an ETF not immediately increase my wealth?
A purchase initially exchanges cash for ETF shares. At the same purchase value, the combined cash and ETF value is unchanged immediately afterwards.
Can an investment result be negative?
Yes. If total wealth is lower than net contributions, the calculated investment result is negative. ETF values can rise and fall.
What happens after a withdrawal?
A withdrawal reduces total wealth and net contributions by the same amount. On its own, it does not change the investment result.
Sources and further reading
- Financial literacy (opens in a new tab)European Commission
- Updated Investor Bulletin: Exchange-Traded Funds (ETFs) (opens in a new tab)Investor.gov, U.S. Securities and Exchange Commission
Related learning
Generavio supports financial education and simulation. Its content is general information, not financial advice.