[canistr]

Well for one, cryptocurrencies (at their current prices) can be divided much greater than simply "1 share". I'm saying that the price that Robinhood sets is dependent on orderbook price which they control.

Example: you buy $20 USD worth of BTC on Robinhood. They give you 0.001750 BTC.

But on other exchanges, you would have received 0.001812 BTC instead. The differing price of BTC between exchanges gives them their "commission/fee".

The lack of transparency in pricing gives them the advantage in exchange for retail consumer confusion over "zero fees".