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.

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.

Since 2011 this is my main modeling platform - no regrets I have been using this platform since 2011. I have used others, even ones that cost 6-digits per year to license and I can honestly say I prefer this one. I have used ClariFI and WorldQuant to name just 2 of the high institutional grade platforms and about 6 others. The P123 simulation engines are lighting fast, they listen to users and are always adding new features...in fact...after 9 years of using the platform I still probably use only 20% of what it can do. A well-rounded system whether you are running simple screens, custom weighed complex portfolios or in-depth research. Any serious family office or smaller firm should take the time to get one of their guys trained on this platform.

Toxic environment Toxic environment that stigmatizes creative, productive, diverse critiques as so-called "unconstructive" and "repetitive" and condones toxic personal attacks.

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.