As a share of the global total, U.S. institutions have the largest slice of that business in 11 years, according to the latest data from Dealogic.

(Read More: Banks Rack Up Profits, but Investors Aren't Happy)

In that period, the banking industry has seen a near-total collapse of the global financial system, the worst economy in more than 80 years and a regulatory regime aimed at retaliating against the banks for the damage they caused.

And yet, investment banking revenues have totaled $11.4 billion so far in 2013, 8 percent more than in the same period in 2012, which was a pretty good year.

That total is good enough for half of the global revenues, up from 47.5 percent last year and the greatest share since the 54.8 percent total in 2002, when the subprime mortgage market was just beginning to heat up. Risky home loans eventually would tank and trigger the global credit crisis.

(Read More: Cheap Money Bankrolls Wall Street's Bet on Housing)

Though margins have been a concern, bank earnings have plowed to record highs.

The top five U.S. bank holding companies—JPMorgan Chase, Bank of America, Citigroup,Wells Fargo and Goldman Sachs—had $8.8 billion of assets at the end of last year, up 3.5 percent from 2011.

The only modest downside has come from merger and acquisition revenues, which have fallen 19 percent, to $4.8 billion. But even there, U.S. banks are dominating the field with a 56.3 percent market share, up from 52.6 percent in the 2012 period.

Congress has sought to stem the possibility of banks' becoming too big to fail (TBTF) again, with questionable results.

In an analysis for clients, FBR Capital Markets sums up the battle this way:

"Critics of the largest U.S. banks are concerned that another financial crisis will produce additional taxpayer funded bailouts. They note that in the past several years, the largest institutions have grown significantly while smaller institutions have failed.

"There are concerns that these largest institutions by virtue of an implied government backstop and their status as TBTF receive a subsidy by the markets that [gives] them an unfair advantage vis-a-vis smaller banks."

(Read More: Foreign Holdings of US Securities Have Exploded)

But FBR concludes that legislation aimed at making sure big banks have 15 percent capital against assets probably won't do much to slim down banks or affect their profitability in a meaningful way.

"At this time we do not see a materially negative outcome on the largest banks. That said, we would not be surprised for the regulators to work on tightening standards and requiring additional capital to have a provision they can point to as specifically ending TBTF.

"A downside scenario could see more aggressive oversight of certain banks regulators deem to have overly complicated and interconnected business lines and force the divestment of certain activities or higher capital charges."

In the meantime, big banks keep chugging along.

The scorecard for investment banking has JPMorgan in the lead, with an 8.5 percent share of the pie, Bank of America second at 7.6 percent and Goldman Sachs coming in third with 6.6 percent.

Follow Jeff on Twitter @JeffCoxCNBC.com.

