Poland
Register a JDG and choose a regime; ryczałt (~8.5–17%) is often the lowest effective option once fixed ZUS is factored in. Exact rate for this activity needs confirmation.
Business income from registered self-employment (działalność gospodarcza / JDG) — not private capital gains.
Choose: ryczałt (lump-sum on revenue, commonly ~8.5–17%); flat 19% on profit; or scale 12/32%. Correct ryczałt rate for trading services should be confirmed.
ZUS social (largely a fixed monthly amount) + health contribution (varies by regime). Reduced 'ulga na start' initially.
Register a JDG; pick a tax form; ryczałt available if prior-year revenue ≤ €2M. Residency >183 days = worldwide taxation.
USDC for services is business income at PLN value on receipt; Poland also taxes private crypto disposals at a flat 19% — interaction is nuanced.