Been reading Futures Truth magazine and considering buying or leasing a trading system and what I would want to know beforehand. This would also apply to systems on http://www.collective2.com/ and similar websites. Below is a list I started. Would be interested in any additions ... 1. When was it released? 2. What updates have there been since the initial release? 3. What are the reasons for the updates? 4. How many traders are trading the system? 5. How many parameters does it have? 6. Do customers receive the source code (i.e. is the system fully disclosed)? 7. What markets does it trade? 8. How long does an average trade last? 9. What is the P/L of an average trade? 10. What is the profit factor of the system? 11. What is avg win/avg loss ratio? 12. What percent of trades are profitable? 13. What amount of slippage and commission were used in the published results? 14. Was the system tested with out of sample data? 15. Are walk forward testing results available? 16. Are in sample and out of sample performance summaries available? 17. Are in sample and out of sample equity charts available? 18. What was the amount and date of the maximum drawdown? 19. How long did the maximum drawdown last?