Some JPMorgan Chase customers who checked their accounts overnight found hundreds or even thousands of dollars missing, and in some cases, added.

"We know some customers reporting seeing incorrect balances in their checking account overnight," Chase said in a statement on Sunday morning, June 28. "This was caused by a technical issue that delayed updates on what displayed on Chase Mobile and Chase Online."

The company said the issue was resolved at 9 a.m. Eastern Time and "accounts now show current balances."