Total loans at the 25 biggest U.S. banks comprise less than 46% of their combined assets, down from 54% this time last year. The figures provide a fresh reality check for an industry that’s been playing up its support for businesses and households as the Covid-19 pandemic ravages the economy. While the total amount that banks have loaned out has stagnated, the nation’s biggest lenders have rapidly expanded other parts of their businesses, such as their holdings of Treasuries and government-backed mortgage securities.