FBI spokesman Joshua Campbell told Reuters: "We are working with the United States Secret Service to determine the scope of recently reported cyber attacks against several American financial institutions."
Though the extent of damage is not clear, around seven of the top 15 banks are expected to have been affected by the attacks.
None of the banks, including JPMorgan, confirmed the attacks.
According to people familiar with the developments, JPMorgan has been a victim of a recent cyber attack, which the bank is investigating.
JPMorgan Chase spokeswoman Patricia Wexler said: "Companies of our size unfortunately experience cyberattacks nearly every day.
"We have multiple layers of defense to counteract any threats and constantly monitor fraud levels."
JPMorgan has asked its customers to report to the bank if they find any suspicious activity on their accounts.
Russian hackers are suspected to be involved in the breach, as a retaliation to the recent sanctions imposed on the country by the US, media reports said.
