We reinvest twice as much after a gain as after a loss, even though (rationally speaking) we should reinvest everything.
In a new paper published by the National Bureau of Economic Research, Steffen Meyer of the University of Denmark and Michaela Pagel of Columbia Business School looked at a massive dataset of over 100,000 retail investors in Germany, examining 10 years of transaction history — including trading behaviour, balances, even log-in behaviour.
