Since we already pay broker commission to enter and exit a trade, then why is the spread charged on top of that. IOW, why don't brokers just charge the spread, and make bid/ask the same price? It seems that most brokers charge spread plus commission fees. Is this just the cost of doing business? Do the commissions for entering/exiting trades and commissions from the spreads both go to the broker, aside from the small amount that goes to the exchange? In the above, I'm referring to stocks, futures, and forex. However, for forex, Oanda says it only charges the spread and no commission, though I doubt the reality of Oanda's 1.5 pip spread on EURUSD.