Excellent site for backtesting equity trading strategies Excellent site for testing stock and ETF trading strategies. P123 provides a thorough point-in-time database with a powerful and flexible engine to simulate backtests of systems. And they integrate with Interactive Brokers to automate applying those strategies to live trading.

I really like P123 works I really like P123 works. The criteria for screens are easy to create and change. It's not a dumbed down version like I've seen on other sites. The backtesting is an interesting and useful feature. To get a 5 star rating you would need to (1) change FCF to exclude dividends (that is so weird and causes me more work to get around), (2) add Invested Capital as a criteria in screening (this would also save me a lot of work), and add foreign stocks to screening universe (I wish you luck in this endeavor. At this point I cannot contribute.)

screens work ..get back testing or you… screens work ..get back testing or you will not really know what is best. Probably need a month or two of back-testing to get things tested and tuned for your needs. that's the Basic Public Screen plus testing them with the different Setting/Ranking methods is a lot of combinations to start from. Then you can tweak for bad /good market situations.

Great Tool Great Tool, great team, great support. I am a very satisfied user for 9 years. I have spent countless hours on it. Only concern: their are dependent on data providers policies. It may occasionally result in changing data or pricing. Backtest servers are much faster and more reliable than in 2 other similar platforms I have tried.

Very flexible stock screening and backtesting platform This is the best and most flexible platform for stock and ETF screening, ranking and backtesting I know. With main focus on fundamentals, you can test, combine and vary hundreds of parameters. No programming knowledge required. One restriction: Portfolio123 does not support intraday trading.