The Millionaire's Guide to the Stock Market: [Money Management] How to Test the Waters before Committing in Currency Trading, Fx Trading, and Forex Trading

A very simple rule I learned long ago is that you should never risk more than the initial margin of any currency lot you trade. That means that you should never risk more than $380 as an absolute maximum you can risk trading currency per lot.
http://bit.ly/1CnUSc9