Unlike centralized exchanges (e.g. NYSE, AMEX, CBOE, and etc.), OTC item prices settle upon agreement of two private parties, unregulated. The Forex brokers understand this and exploit it for profit.
These bucket shops trade against the clients, i.e. they serve as market makers and more often than not take the other side of trades against clients. They understand statistically that most financial market traders perform with negative expectancies, hence making trading against a losing crowd profitable business. This aslo explains why they target and welcome financial industry newbies so much.
What about the ones smart enough to eventually trade profitably? These brokers operate to preserve capital, and they resort to whatever means available and prevent consistent winnings off any client. Software disconnects, lagging/fraudulent price quotes, unfilled orders, or simply account banning have become some, certainly not all, common bucket-shop practices.
The above explains why most Forex brokers have incentives for clients to lose, and hence not legitimate. It has given Foreign Exchange trading a bad name, though it can become lucrative still, just not through the typical bucket-shops.
