Ginmon TopZins is an investment with a variable interest rate, where the rate is linked to the current Euro Short-Term Rate (€STR). The interest rate always matches the Euro Short-Term Rate (€STR) plus 8.5 basis points, making it roughly equal to the ECB deposit rate. Interest rate adjustments only occur when the ECB key interest rate is raised or lowered, not due to discretionary decisions by Ginmon.