Interactive Brokers

For our ETF investor (CHF 50,000 portfolio, four ETF buys of CHF 5,000 on SIX), the bill is four commissions of CHF 5 and nothing else. No custody fee, no account fee, no inactivity fee, and no Swiss stamp duty, because foreign brokers don't charge it. Saxo, the cheapest Swiss bank, costs CHF 46 for the same profile. UBS costs CHF 399.

Currency conversion is where IBKR really pulls away. It charges 0.002% with a USD 2 minimum, so converting CHF 8,000 into dollars costs about USD 2. At a broker charging 0.95%, the same conversion costs CHF 76. If you buy US stocks or USD-listed ETFs, that gap alone pays for years of commissions.

135 markets from one account. Stocks, ETFs, bonds, funds, options, futures, CFDs and forex, plus fractional shares and recurring investments. Nobody else in our table comes close: Swissquote offers 31 markets, Saxo 19. You also get a CHF IBAN for deposits and a demo account, so you can test the platform before you send it a franc.

IBKR is a US group founded in 1978, but your contract is with Interactive Brokers (U.K.) Limited, supervised by the UK's FCA. It isn't a FINMA-licensed bank, which you can check yourself in FINMA's list of authorised institutions. Your securities are segregated client assets. What you give up is esisuisse, the Swiss protection for cash.

IBKR doesn't issue a Swiss eTax statement itself. At tax time you either list every position yourself or pay a third-party service to build the statement for you. That's an extra cost and an extra step that Saxo and neon handle for free. It doesn't erase IBKR's cost lead, but put it in your budget from day one.

Two more traps catch Swiss investors. Sign the W-8BEN form so US dividends are taxed at 15% at source, which you then claim back through the DA-1 form. And prefer Irish-domiciled ETFs over US-domiciled ones, which can expose your estate to US estate tax. Neither is IBKR's fault, but a foreign broker won't remind you.

If cost is your main criterion, IBKR wins for almost every profile, and by a huge margin for active traders: CHF 149 a year versus CHF 1,013 at Saxo. The trade-off is a busier platform, a UK contract and DIY tax paperwork. See how it stacks up against the other nine in our best brokers in Switzerland ranking.

Verdict: The cheapest serious broker for Swiss residents, as long as you're fine without esisuisse and a built-in eTax statement.