The Consumer Financial Protection Bureau has finalized a rule that curbs excessive overdraft fees charged to customers of large banks and credit unions, potentially saving consumers as much as $5 billion a year.The rule, unveiled Thursday, would cap overdraft fees at $5 — a substantial savings from the $35 that customers are typically charged. In total, households could save about $225 per year. Additional options for banks would allow them to either cap fees at amounts that just cover their costs or to treat an overdraft like any other loan by disclosing terms like interest rates.”For far too long, the largest banks have exploited a legal loophole that has drained billions of dollars from Americans’ deposit accounts,” Rohit Chopra, the bureau’s director, said in a press release. “The CFPB is cracking down on these excessive junk fees and requiring big banks to come clean about the interest rate they’re charging …