I reported this story with Thomas Erdrbink, the Tehran correspondent, and David Kirkpatrick, an international correspondent based in London. This story appeared on the front page on Sunday January 21, 2018. 

At 25 percent, the interest rate paid on a savings account at the Caspian Finance and Credit Institution in Tehran was a better return than Mehrdad Asgari could earn investing in his own business renting out construction equipment. So in December 2016, he jumped at the chance, depositing $42,000 in a savings account.

Before long though, Caspian stopped allowing withdrawals. After three months, it stopped paying interest. Finally, in May, it shut its doors for good — becoming one of the largest in a long series of failures of Iranian financial institutions in recent years. The closings have destroyed the savings of thousands of people, imperiled the banking system and helped fuel the antigovernment protests that roiled the country late last year.

Read the rest of the story here.