The trading debacle has been a legal and reputational black eye for the largest U.S. bank. JPMorgan's losses stemmed from bets by London-based Chief Investment Office trader Bruno Iksil on an index for credit default swaps. His outsized positions earned him the nickname "London Whale" from hedge fund traders taking the other sides of his positions.
CEO Dimon was criticized for initially dismissing rumors of a troubled trading position as a "tempest in a teapot" during an April conference call. Less than a month later, the bank disclosed problems with the trading strategy, and later said it lost $6.2 billion from the trades.
The Senate panel based its findings on 9 months of investigation, 90,000 documents and 50 interviews and briefings.
Experts said disclosures from the hearing and the Senate report could provide ammunition to securities regulators and investors pursuing the bank for misconduct over the trades.
"Clearly this report digs up a lot of evidence that can be used in various legal proceedings," said James Angel, a visiting associate professor of finance at the Wharton School of the University of Pennsylvania. "I'm sure the plaintiffs bar is looking at this very carefully and rubbing their hands with glee."
The report could also assist the various investigations being conducted by the Justice Department, the Federal Bureau of Investigation and the Securities and Exchange Commission.
A person familiar with the SEC's inquiry said investigators are focused on how quickly and accurately the bank disclosed the problems in SEC filings, shareholder calls and press releases. The Senate report suggests they were not getting full disclosure.
The SEC and Jennifer Zuccarelli, a spokeswoman for JPMorgan, declined to comment.
The report also gives ammunition to advocates calling for stricter financial reforms, including to regulators crafting the Volcker rule, which proposes to put limits on banks betting with their own funds.
"If derivatives books can be cooked as blatantly as they are in this case without breaking the rules, then the rules need to be revamped," said Levin, a Democrat.