Wall Street banks made about $85 million in fees on Snap (SNAP)'s giant IPO, with Morgan Stanley (MS) and Goldman Sachs (GS) taking the lion's share.

According to SEC filings, lead underwriter Morgan Stanley got 60 million Snap shares, or, 30.2 percent of the shares given to underwriters — which would mean $25.71 million in fees, the biggest cut of any bank.

The second biggest —Goldman — sold nearly 50 million shares, or 24.8 percent, amounting to about $21.08 million.

Other big chunks went to JPMorgan and Deutsche Bank, while a slew of more than 20 other banks sold slivers, each less than 10 percent. (Some of these banks could also have been paid additional fees that haven't yet been disclosed.)

Here's how it works: A group of banks work with Snap and potential early IPO buyers -- mainly large institutional investors -- to figure how how many shares they'll be able to sell at what price. The banks keep a percentage of the total amount raised, and give the rest to Snap. That percentage is subject to negotiation.

Snap's $3.4 billion IPO raised more than twice as much as every 2016 venture-backed tech IPO combined, according to Renaissance Capital. But the 2.5 percent underwriting fee for the banks could be the third-lowest ever for a major technology offering, the Wall Street Journal reported earlier this year.

Snap's IPO underwriters had a difficult task, Recode reports: They wanted to make sure the IPO price was not too high or too low before it hit the public market, as early investors and founders of the company wanted a fair deal.

Here are the banks that underwrote the IPO, and the number of shares they received.

Correction: This story originally misstated the way IPO underwriting works.

— Reporting by CNBC's Dawn Giel