Trump’s Call for 10% Credit-Card Cap Aims at Banks’ Crown Jewels

President Donald Trump’s demand that credit-card lenders cap interest rates at 10% for a year takes aim at one of the banking industry’s crown jewels — a business line they guard doggedly.

After a week of jarring markets with announcements aimed at making homes more affordable, the president swiveled to another consumer burden: the cost of carrying a credit card balance from one month to the next. This time, his social-media missive pushed a slew of card issuers led by JPMorgan Chase & Co., Capital One Financial Corp. and Citigroup Inc. into the crosshairs.

Card interest rates — ...