Brokerage account currency — why it can eat your profit
Definition
The "currency structure of the account" is how a broker handles currencies when you buy assets quoted in, say, dollars or euros while you deposit złoty. It is one of the least obvious yet genuinely costly elements of investing in foreign shares and ETFs.
What it means in practice
- Forced conversion (double FX). Some accounts hold a balance only in PLN. Buying a share in USD, you pay conversion on purchase (PLN→USD), and on sale a second one (USD→PLN). That is two spreads per round trip — a cost not visible in the commission.
- Native currency sub-accounts. Other accounts let you hold a balance in USD/EUR/GBP and convert once (or fund the account directly in the currency). Buying and selling then happen without forced FX — with frequent trading the difference can be significant.
- The spread is often hidden. The conversion cost is often a spread (a difference in rate), not an explicit commission — so it's easy to miss when comparing only the "per-transaction commission".
Why it affects your choice
Two accounts with identical commission can genuinely differ in the cost of investing in foreign assets precisely because of the currency structure. It is one of our deliberately highlighted parameters, because it is often overlooked.
How to check this in our comparison
The "Currency structure" field for each broker in the Investing lens (e.g. "PLN only — double FX" vs "currency sub-accounts"), with source and date. Order is alphabetical, not a ranking.
Watch out
Conversion rates can be variable and not published explicitly (baked into the spread) — confirm the current cost with the broker. The benefit of currency sub-accounts depends on how often you trade and whether you have income in that currency.
We do not give investment advice. Conversion costs can vary — confirm with the broker. Investing involves the risk of losing capital. WTP Finance is for information only.