America’s biggest banks are off to a steady but unspectacular start to earnings season. Results on Tuesday from JPMorgan Chase, Wells Fargo, and BlackRock show, as expected, gains coming from trading activity and deal-making. At the same time, blowout numbers mostly failed to materialize. Consumers showed up in somewhat weaker lending margins, as spending stayed solid while showing some signs of deceleration. All in all, it was a good quarter for the big banks by any normal measure — just not a spectacul ...