Donald Trump’s election to US president is the best thing to happen to big banks in a very long time, as far as markets are concerned.

The share price of Goldman Sachs closed at a record high yesterday, on the day Steve Mnuchin, a second-generation veteran of the investment bank, was confirmed as US Treasury Secretary. Goldman’s shares have rallied by nearly 40% since the Nov. 8 election.

Goldman is the standard bearer for the post-Trump bank bonanza because, although he had few kind things to say about Wall Street during the campaign, the new president has surrounded himself with former Goldman execs after taking office. Gary Cohn, the former president and COO of the bank, is now the director of the White House’s National Economic Council. He and Mnuchin will oversee the most important aspects of US economic policy, including a push to dismantle the Dodd-Frank Act, a key piece of post-crisis financial regulation.

The combination of lighter regulation, tax cuts, higher interest rates, and a boost to fiscal spending is a powerful one for big banks’ balance sheets. As a result, investors have bid up the value of the six largest US banks’ shares by a whopping $280 billion since the election.