We analyze how individuals reinvest realized capital gains and losses exploiting plausibly exogenous sales due to mutual fund liquidations. Individuals reinvest 83% if a forced sale results in a gain relative to the initial investment; but reinvest only 40% in the event of a loss. This difference is statistically significant for more than six months and arises because many individuals forced to realize a loss choose not to reinvest anything and some even exit the stock market altogether. Individuals treat realized losses differently from paper losses and are discouraged from investing more and participating in the stock market.

Using an experiment in which 3.1 million bank customers were encouraged to save, we explore the mechanisms behind coholding liquid savings and credit card debt. Theoretically, we show that the joint responses of spending, saving, and borrowing to the nudge differ across economic models of coholding. Using machine learning techniques, we find that the most responsive individuals reduce spending and increase savings by 4.9% (206 USD PPP per month) while their credit card debt remains unchanged. These individuals' marginal responses to the nudge are consistent with our model of coholding for the purpose of self‐ or partner‐control.