Except capital gains taxes don't include inflation in the calculations. So let's say your stocks in aggregate rose 4% that year, and the inflation was 3%. You

Except capital gains taxes don't include inflation in the calculations. So let's say your stocks in aggregate rose 4% that year, and the inflation was 3%. You made 1% profit (in purchasing power). You pay 4% * 0.15 = 0.6% which is 60% of your profits and only 38% of your income.