A proposed 10% cap on credit card interest rates could restrict access to credit for millions of Americans. Industry experts agree that a 10% interest rate cap could lead to the cancellation or severe restriction of credit card accounts for up to 90% of cardholders – specifically those with credit scores below 740.

U.S. financial stocks and UK-listed lenders fell on Monday and weighed on global indexes as President Donald Trump's call for a one-year cap on credit card interest rates threatened a key revenue stre...