All told, December was the biggest month in history for offerings, according to Thomson Reuters.

Here’s what the post-bailout bonanza means for all the banks that helped find investors for the new shares: Bank of America’s $19.3 billion offering generated $482 million in fees; Citigroup’s $17 billion offering resulted in $425 million in fees; and Wells Fargo’s $12.2 billion offering led to $275.6 million in fees. (The banks paid themselves roughly 2.5 percent of the offering price.)

Other banks were beneficiaries as well. As part of the Citigroup offering, for example, Citi syndicated part of the sale to Morgan Stanley, BNP, Lloyds and ING. (Why can’t Citi do it alone? The answer is that to raise that kind of money, you need a little help from your friends, some of whom are better at raising money than others.)

Those fees are likely to factor into the bonuses for the investment bankers involved.

“Ironically, the mechanics of exiting TARP turned out to be lucrative business for equity underwriters this year,” said Matthew Toole, director of the Deals Intelligence unit of Thomson Reuters’ Investment Banking Division.

Mr. Toole ran some numbers and turned up a startling figure: fees over the last two years for follow-on share offerings among financial companies in the United States totaled $5.4 billion. That’s more than the $4.8 billion that was raised in the previous 20 years.

There’s one wrinkle in the case of Citigroup, and it is good news. When the Treasury Department begins to unload its shares in Citigroup  it originally said last week that it planned to sell $5 billion worth, but then said it would delay the sale  the taxpayers are not likely to be asked to pay the fees. Citigroup has privately signaled that it will pay the fees, though  wait for it  Citigroup will participate in the offering itself, so it will in effect pay fees to itself.