"Anybody who's inflicted damage on our financial markets should not be of the belief that they are out of the woods because of the passage of time," Holder said in an interview with the Journal on Tuesday.
He declined to discuss specific cases or say when the cases would be announced, the report said, but added that he wouldn't leave the job before making major charging decisions on cases stemming from the 2008 financial collapse.
There has been widespread speculation that Holder wouldn't serve through the end of the Obama administration.
Holder's comments come as the U.S. government takes steps to hold companies responsible for breaking the law in financing the housing bubble that led to the financial crisis.
He said earlier this month that the Financial Fraud Enforcement Task Force would continue to take an aggressive approach to combating financial fraud and uncovering abuses in the residential mortgage-backed securities market.
Disclosures this month from some of Wall Street's biggest financial firms, including JPMorgan Chase (JPM) and Bank of America (BAC), have shown that the federal government is pursuing new prosecutions of possible abuses in the mortgage-backed securities industry.
"These are complex cases that require enormous amounts of effort to put together, but we are at a point -- as you've seen, I think, recently -- where the results of that difficult work is starting to bear fruit," Holder said in the Journal interview.
Holder declined to answer specific questions about JPMorgan and its chief executive, Jamie Dimon, the report said.
The bank faces at least a dozen investigations on issues ranging from mortgage bonds sold before the financial crisis to a federal bribery investigation into whether it hired the children of key Chinese official to help it win business.
"No individual, no company is above the law. We don't investigate companies based on who a CEO is, but we don't avoid investigating companies based on who the CEO is, either," Holder told the paper.