Monetary policy and bank equity values in a time of low and negative interest rates

Does banks' exposure to interest rate risk change when interest rates are very low or even negative? Using a high-frequency event study methodology and intraday data, we find that the effect of surprise interest rate cuts announced by the ECB on European bank equity values - an effect that is normally positive - has become negative since interest rates in the euro area reached zero and below. Since then, a further unexpected cut of 25 basis points in the short-term policy rate lowered banks' stock prices by about 2% on average, compared to a 1% increase in normal times. In the cross section, this 'reversal' was far more pronounced for banks with a more traditional, deposit-intensive funding mix. We argue that the reversal as well as its cross-sectional pattern can be explained by the zero lower bound on interest rates on retail deposits