There you go - Excise duty planned for outwards remittance from USA . So far it’s for residents I believe.
Imagine if they do this for non-Resident brokerage accounts too. Although I have to say I am not very sure if remittances from USD accounts in IBKR would be exempted or not because technically if they apply this to wire transfer then all money moving out of US by non-US citizen will become part of scope
House Republicans have included in President Donald Trump’s big priority bill a 5% excise tax on remittance transfers that would cover more than 40 million people, including green card holders and nonimmigrant visa holders, such as people on H-1B, H-2A and H-2B visas. U.S. citizens would be exempt.