Broker price vs true return

The green or red percentage in your brokerage app almost never equals how your euro wealth compounded — dividends, fees and FX are missing.

1. What brokers usually hide

  • Paid-out dividends and bond coupons leave the position line.
  • No day-exact timing (1 month vs 8 years).
  • USD/CHF FX between buy and valuation day.
  • Fees, accrued interest, partial sales / FIFO cost basis.

2. FX formula (ECB quantity quotation)

(1 + r_EUR) = (1 + r_local) × (FX_buy / FX_valuation)

FX = foreign units per 1 EUR. If EUR/USD falls from 1.10 to 1.05, the dollar strengthened: FX effect 1.10/1.05 − 1 = +4.76%.

3. World ETF case A vs B

Buy $10,000, +8% price to $10,800, +$200 dividend after one year:

Case A (USD stronger 1.10→1.05)Case B (USD weaker 1.05→1.12)
Broker USD price+8.00%+8.00%
Euro XIRR (approx.)+15.24% p.a.+3.13% p.a.

Interactive: FX calculator · XIRR calculator. German full article: Broker-Kurs vs. echte Rendite.