Aim: The paper measures the impact of negative interest rates on listed firms in the original euro zone countries. It also measures the impact of the first COVID-19 year.Design / research methods: The paper uses panel data to measure the influence of the short-term ECB deposit rate and the 10-years German bond yield on short-term and long-term firm variables. Cross section fixed effects are applied to first differences and dummy variables. For liquidity and non-liquid assets the effects are also measured for small and large companies, for sectors, and for countries.Conclusions / findings: Corporate liquidity ratios and creditor ratios decline when short-term ECB-rates fall. If ECB rates are negative, liquidity ratios are further reduced by ...