Major Australian companies and superannuation funds operating in the United States face a 20 per cent tax increases on investments, in a Republican push to retaliate against countries deemed to discriminate against American businesses through measures such as this country’s Pharmaceutical Benefits Scheme.

Big superannuation funds have $400 billion invested in the US, and generally do not pay capital gains tax from these investments. However, that could change due to a budget proposal being debated by Congress, known as the “one big beautiful bill” backed by the Trump administration.