WASHINGTON — JPMorgan Chase will pay $153.6 million to settle civil fraud charges over misleading investors into purchasing complex mortgage securities just before the housing market collapsed.

The settlement with the Securities and Exchange Commission announced today is one of the most significant legal actions targeting Wall Street’s role in the 2008 financial crisis.

As part of the settlement, investors who were harmed will receive all of their money back, the SEC said. JPMorgan also agreed to improve the way it reviews and approves mortgage securities transactions.

The bank neither admitted nor denied wrongdoing under the settlement.

Regulators have been investigating a number of major banks and more charges are expected.