We exploit a large reform of capital-gains taxation in Germany combined with portfolio-level daily panel data to study the causal effect of taxes on individual stock-trading behavior and the disposition effect. We find substantial spikes in selling probabilities around an intertemporal tax discontinuity, and no such spikes after the abolishment of the discontinuity. Using difference-in-bunching methods, non-parametric regressions and effective tax rates, we quantify the tax effect and identify interesting patterns of heterogeneity. We further find evidence that the well-established disposition effect is strongly affected by the tax discontinuity through tax motivated selling of both gains and losses.


Taxation, Capital-gains, Private investors, Trading Behavior, Disposition Effect