Sell ETFs or Take a Loan?

Because of capital gains tax. When you sell ETFs at a profit, Germany applies Abgeltungsteuer of 25% plus a 5.5% Solidaritätszuschlag on top — 26.375% all-in. For equity ETFs (Aktien-ETFs), 30% of the gain is tax-free under the Teilfreistellung rule, so the effective rate on those gains is roughly 18.46%. The calculator pro-rates the tax to the share of the portfolio you'd actually liquidate, then adds it on top of the cash you need so you net the right amount after tax.

An Annuitätendarlehen is the standard German consumer/mortgage loan structure: you pay the same fixed amount every month (the Annuität) for the entire term. Early on, most of the payment is interest; as the balance falls, more of it goes to principal. The calculator uses the textbook formula P × i(1+i)ⁿ ÷ ((1+i)ⁿ − 1) with monthly compounding, so the totals match what a German bank would quote. Sondertilgungen (extra repayments) are not modeled in v1.

It's the loan interest rate at which both strategies — sell now vs. borrow and stay invested — leave you with exactly the same net worth at the end of your chosen horizon. If a bank offers you a rate below this break-even, the loan strategy comes out ahead. Above it, selling is the better move. We find it with a binary search across rates from 0.1% to 20%.

If your monthly loan payment is higher than your monthly savings, in real life you would have to top up the difference each month — typically by selling ETFs. The v1 model just clamps leftover savings at zero rather than modelling those forced sales, which makes the loan strategy look slightly better than it really would be. The warning is there so you don't take the verdict at face value when the cashflow doesn't actually work.

A Wertpapierkredit (securities-backed loan) is collateralized by your portfolio, so the rate is usually lower than an unsecured Ratenkredit. The trade-off is margin risk: if your portfolio drops below a certain ratio, the bank can force you to either deposit more securities or sell. For the math the calculator does, you can simply enter the Wertpapierkredit rate as the loan interest rate — but factor the margin risk into your decision, especially over longer horizons.

Yes — for a mortgage on a property you rent out, the interest is fully deductible against rental income, which can change the calculus significantly. This calculator assumes a non-deductible loan (typical for personal purchases like a car, kitchen, or down payment). For property-investment scenarios, see the dedicated property simulator.