Switzerland
Treated as self-employed; ordinary net profit taxed at federal+cantonal+municipal rates (no tax-free capital-gains treatment) plus ~10% AHV. Total rate varies strongly by canton.
Self-employed earned income (selbständige Erwerbstätigkeit) on net profit. The tax-free private capital-gains rule does NOT apply (this is commercial activity).
Federal (up to 11.5%) + cantonal + municipal; total effective commonly ~20–40%+ depending heavily on canton.
AHV/IV/EO ~10% on net self-employment income (no employer to split it), with a minimum.
Register as self-employed with the cantonal compensation office. VAT only above CHF 100,000 turnover. No flat freelancer regime.
USDC is self-employment income at CHF value on receipt; crypto holdings also face annual cantonal wealth tax.