Here's a couple from me:
- Ability to freely exchange between cryptocurrencies and the stock exchange. That would be rad.
- No fees. Believe it or not this is actually possible, for example Robinhood (a stock trading app) does not charge any fees when purchasing stocks. They way they do this is by investing the spare money in your account that isn't invested in stock.
I believe that both of these are opportunities for those of you considering starting an exchange.
people in crypto who are trading it, specially the altcoin traders have no interest in stocks. the profit you can gain in an altcoin is ridiculously high that you won't waste your money by making it stuck in a stock
the no fees feature is obviously always something that attracts a lot of people but only if it is possible to do and not end up doing shady things in the background like fake pumping coins yourself (the exchange i mean) to make money.
but the most important feature of an exchange that everyone is looking for is "trust". we have seem multiple times that exchanges easily run away. if we can solve this somehow it will be cool.
the other thing is anonymity. these days the big exchanges have even started asking for verification. we are using currencies for god's sake! asking for verification is absurd.