Jeremy Grantham's right-hand man says the S&P 500 is still 30-40% overvalued — and tariffs just sank its best bull case

Trump's tariffs threaten the US stock market's appeal, says Ben Inker of GMO. - Tariffs could hurt large-cap growth firms' profit margins, impacting market performance. - Inker advises investing in non-US stocks due to valuation discounts and economic risks in the US. President Trump's tariff…