The benefits of forex over currency futures trading are considerable. The dissimilarities between the two instruments range from philosophical realities such as the history of each, their target audience, and their relevance in the modern forex markets, to more tangible issues such as:
More Volume = Better Liquidity
Daily currency futures volume on the CME is just 1% of the volume seen every day in the forex markets. Incomparable liquidity is one of many advantages that forex markets hold over currency futures. Truth be told, this is old news.
Any currency professional can tell you that cash has been king since the dawn of the modern currency markets in the early 1970′s. The real news is that individual traders from every risk profile now have full access to the opportunities available in the forex markets.
Minimal or no commissions
With Electronic Communications Brokers (more on this later) becoming more popular and prevalent over the past couple of years, there is the chance that a broker may require you to pay commissions. But really, the commission fees are peanuts compared to what you pay in the futures market. The competition among brokers is so fierce that you will most likely get the best quotes and very low transaction costs.
When trading forex, you get rapid execution and price certainty under normal market conditions. In contrast, the futures and equities markets do not offer price certainty or instant trade execution. Even with the advent of electronic trading and limited guarantees of execution speed, the prices for fills for futures and equities on market orders are far from certain(see also order type). The prices quoted by brokers often represent the LAST trade, not necessarily the price for which the contract will be filled.