WHEN Donald Trump won America’s presidential election 14 months ago, banks’ share prices leapt. One reason for that was the prospect of lower corporate taxes, which would both benefit banks directly and (investors hoped) ginger up the economy. Like Mr Trump’s legislative agenda, their shares were becalmed for much of 2017, but they perked up late in the year when the Tax Cuts and Jobs Act looked likely to become law—as it duly did when the president signed it on December 22nd.
Yet several banks expect the act to make deep dents in fourth-quarter profits. On December 28th Goldman Sachs said it was braced for a $5bn hit. A week before, Bank of America (BofA) announced a $3bn write-down. Early in the month, on fairly accurate assumptions about the law’s final form, Citigroup put the cost at a whopping $20bn. Foreign banks are also assessing the damage: £1bn ($1.4bn), says Barclays; SFr2.3bn ($2.4bn), reckons Credit Suisse.