Re market makers and their fees --
Once a stock is on the market, market makers make their money from trades.
For a stock to get on the market in the first place, however, an initial market maker has to be found who agrees to 'make a market' for the stock. That requires the market maker to have inspected the stock's financials so that 'he' can, in turn, vouch for the stock that he agrees to start making a market for (i.e., be a middle-man who facilitates the trades). Once an initial market maker (MM) has done the due diligence, there's a rule that says others can 'piggy-back' off the work of the first MM.
The work that has to be done by the first MM probably has to be paid for, especially since that first MM has a lot to lose if he is found guilty of making a market on a 'bad stock.' MMs can be fined and sanctioned by FINRA, which includes having their credentials to be a MM (or broker-dealer) pulled.
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