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.

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.

Portfolio123 is a game-changer for… Portfolio123 is a game-changer for stock investors, providing a powerful platform for the design, simulation, and deployment of quantitative financial models. It also has stock screening, charting (including YChart style), trading (via Interactive Brokers and Tradier), macro economics charting, watchlists, an earnings center, cross-section series plotting, external data importer, a data API, stock news, stock summary snapshots, stock comparison tool, sector/Industry performance, fundamental and estimate summaries, a user forum and more (really). In the near future, machine learning will be supported. It's not just another retail-level tool; it's the only one that I’ve found to work in practice. To find something better, I suspect you'd have to go professional and spend significantly more. I've been a loyal subscriber for over a decade, which speaks volumes about its effectiveness. Is there a downside? Sure, building successful trading models is hard work, but with dedication and focus, it's possible to be successful. Whether you're researching stocks, building and simulating quantitative models, or managing accounts, Portfolio123 has what you need.

Love the screening with backtests Love the screening with backtests. Forum members are very helpful. Would like access to more foreign markets, log charts, and ability to trade with entry and exits at the $100/mo level.

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.