Mechanical trading If all done well… - Your hard work that lasts for a long months that is dedicated to creation and testing of your mechanical trading system is over. There is no stress, since you will not be glued to the market and your system will make trades by itself. You have superb confidence with it, since you have included all aspects and potential surprises that could market give you; - This system generates sufficient money cash flow that allows you to live as you want and look at your growing profits from time to time; In reality something is always wrong… - Since you have tested your system on historical data, you are not absolutely sure that it will work with same results in reality. You have to spend days and weeks with your PC for optimization and testing after you’ve launched it; - When you see one large drawdown, then another one – you start to worry about your trading capital, and decide for diversification develop 1, 2 or may be 3 another systems that will smooth drawdown; - Stress reaches crucial levels, when you see how your system bombs your trading account and you can do nothing, except just following its orders; - Suddenly you understand that sum that you reserved as potential spread + slippage seemed to not be enough; - You have to pay more and more to software programmers. Can you be sure that they have done all the stuff correctly? - Sooner or later all mechanical systems will break.