Aren't all orders eventually public anyway? I get that the liquidity that "market makers" claim to create is not really that beneficial to society, but as long as you're not trying to use robinhood to compete with the high speed traders, I don't see a problem with it.
Not doing so or at least in a condescended form is kind of operating a fraudulent exchange. It is kosher to bundle 50 buy orders of 1 stock into 1 order or visa versa - get a bunch of little orders that adds up to a cheaper option. If it doesn't work out refund and inform that it failed to go through. If they asked for 1 share at $25 and you legitimately give it to them it isn't fraud. It is another to say "buy" Tesla shares for people when you really shovel it into another investment and work out what they owe when you think they will just go bankrupt and Theranos is the way of thw future....
no. most orders are not executed on the public exchanges, but by internal matching via your broker and a market maker. (also most exchanges only support trades in multiples of 100 shares.)
Exchanges handle odd lot orders nowadays. Maybe some brokers or dark pools do not, but they are not exchanges (their quote is not protected, or they show no quote).
I believe all customer trades/executions on actual securities should eventually be publicly visible, though there may be a small delay for them to "print to the tape".
