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.

Extremely powerful and unique tool Extremely powerful and unique tool. Im not aware of any other like it on the market. Despite having no formal finance background I have decisively beaten my benchmark index for multiple years with real money investing in companies that are off most other people's radar. Once you get used to systematically investing with a model you will wonder how you did it any other way (or how you could do it any other way). The staff is extremely knowledgable and responsive. The user community is generous and supportive. Beyond that, the tool is just fun to research, test theories and play around with.

Nearly 10 Years of Superior Service - Small Token of Appreciation Number one priority for any serious investor is 'quality of data', as well as functionality and ease of use. P123 is easy to learn and get going with, and allows you to learn fundamental factors/codes at your own pace. I have been using the service for nearly 10 years now, and it is very much a part of my development (still ongoing) as a disciplined investor/analyst religiously focused on company fundamentals (and a sprinkle of technical timing). No screener, or backtesting software is worth it's salt without the highest quality and integrity of data. And P123 scores 5/5 on that highest priority. It's been good to me - hence this lengthy review as a small token of appreciation.

Extremely powerful tool Extremely powerful tool. I have been using it for almost two decades. There is nothing else like it available to the general public. I have gotten great results.

Portfolio123 is an awesome site with so many tools Portfolio123 is an awesome site with so many tools to help investors. They are very responsive and they are often on message boards with help and will respond to emails as well.