South Dakota brokerage account growth calculator

What a taxable index-fund account is actually worth after expense-ratio drag and after South Dakota takes its share of the gain — which, in most states, is not at the federal preferential rate.

South Dakota does not tax capital gains

Your gain is untouched by South Dakota. Only federal tax applies. No state tax on capital gains, short-term or long-term, and no standalone capital gains excise of the kind Washington enacted in 2021. This is the contrast that matters for an investor comparing the no-income-tax states: in South Dakota "no income tax" and "no tax on investment gains" are the same statement, and in Washington they are not.