Reasons

* Contracts do not expire
   Unlike Options (option trading) where you have an expiry on the contract and when that date comes close the option is worth next to nothing, the contracts in the forex market keep rolling forward until you decide to close the trade out.

 * Best Trending Market
   Trends are the key to profitable trading and this is what makes trading the forex market so popular. Currencies consistently out perform all other markets including stocks, bonds and other commodities.

 * Simplicity
   The simplicity of following only a small number of currencies, instead of watching hundreds of stocks, makes forex trading enjoyable and even relaxing.

 * You cannot go lower than your account balance
   In the forex market, if a trade goes against your position and you were trading without a stop (something that is not recommended) you only face loosing your trading balance. Your position will most likely be closed out by a margin call, thus protecting your other assets (home etc...)

 * Banks Choose to Trade Currencies
   Banks are big players in the foreign exchange with banks making 60% of their income from the forex market.

 * Free Unlimited Demo Accounts
   The ability to trade using a demo account until you feel comfortable using real money.

 * Free Charts
   The cost of data used to trade options or other commodities can be as high as $300 a month. With forex, you have the choice of free charts and data, or paid charts.