When you buy/sell shares at market price (not using limits), what rules must your broker follow?
You tell your broker to sell shares at market price. The broker buys the shares immediately, waits a few hours, and then sells to you at the highest price that occurred since you purchased the stock.
Two people with the same broker are posting a buy and sell for market price at the same time. The broker takes the sellers stocks and sells them to the buyer. Could the market price for the buyer be different from the market price for the seller?
Are these considered ethical or legal? What are some readable sources that outline the rules that brokers must follow?