A federal securities filing shows that Robinhood was paid $331 million by market-makers that execute stock and options orders for the broker’s clients in the first quarter, when the GameStop frenzy grabbed hold of the market.

Basically, Robinhood routes its orders to high-frequency trading firms that match buyers and sellers and profit from the spread between the buy and sell price.

Customers who hold stocks for months are not as lucrative to Robinhood as those who make dozens of trades a month, earning the broker commissions with each trade.

Some analysts believe the figure at Robinhood is well above 50%. Bell estimates that the number is closer to 70% to 75%, although that is down from her prior call of 80%. Using those assumptions, it’s possible to derive a rough estimate of revenue for Robinhood, though it is important to note what isn’t covered by the disclosures of payments for order flow.

The filing doesn’t include crypto trading, while Robinhood makes money from crypto trading in similar ways that it profits from stock trading.

The company said that 9.5 million customers traded crypto on Robinhood Crypto in the first quarter of 2021, compared with 1.7 million in the fourth quarter of 2020.

Even excluding crypto, Robinhood likely made more than $400 million in the first quarter, after including money it makes from enhanced services like Robinhood Gold.