The Securities and Exchange Commission has been mightily criticized in recent weeks for what some see as its inactivity in corralling errant companies for their financial misdeeds, but today the agency shot back.

It announced that it had brought a record number of insider trading cases in the 2008 fiscal year, which ended September 30. It also chalked up the second-highest number of enforcement actions in its history over the same time, and returned more than $1 billion to investors who had lost money.

Even so, the numbers aren't likely to quell critics of the agency or its chairman, Christopher Cox. Both are likely to come in for more opprobrium tomorrow, when Cox is due to appear before the decided unfriendly House Oversight and Government Reform committee.

Of course, this follows Cox's very public kneecapping by Republican presidential candidate John McCain, who said if he were president he would fire Cox—never mind that he serves a defined term.

As documented in a recent Condé Nast Portfolio article, Cox has undercut his enforcement staff, leading to smaller, less-significant cases being brought against wrongdoers.

And questions have been raised about contact between the enforcement staff and big players on Wall Street during the current economic crisis.

In a report issued earlier this month, the commission's inspector general said that Linda Chatman Thomsen, director of the commission's division of enforcement, and two supervisors should be disciplined for their role in an insider-trading probe.

Senator Chuck Grassley of Iowa, the ranking Republican on the Senate Finance Committee, followed up with a letter to Cox asking about inappropriate contact between Thomsen and J.P. Morgan's general counsel while the investment bank was considering a bid for Bear Stearns.

Even its own inspector general has criticized the S.E.C. Just last month, it issued a lengthy report on the commission's initiative to let financial institutions regulate themselves. A chastened Cox responded by acknowledging that "voluntary regulation does not work."

Still, the commission is taking a glass-half-full approach to self-assessment. In its announcement today, the commission said it has greatly stepped up its profile as the defender of the investor.

During the last fiscal year, the commission brought 671 enforcement actions. Insider trading cases were up more than 25 percent, and market manipulation cases up more than 45 percent. One of its highest-profile actions was the prosecution of a $24 million insider-trading case against former Dow Jones board member David Li and three others.

The commission added that it has more than 50 ongoing investigations relating to the subprime mortgage market.

One of the major fraud cases the S.E.C. brought last year was one against two Bear Stearns hedge fund managers on charges they fraudulently misled investors about the financial state of the firm's two largest hedge funds.

The agency also brought charges against 10 insiders or promoters of publicly traded companies who made stock sales in exchange for illegal kickbacks.

And the commission said it has reached preliminary settlements with six of the largest firms in the auction rate securities markets. Those settlements, which are not included in the 2008 enforcement statistics, could return more than $50 billion to investors, the commission said.