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.

Fantastic product for individual investors If you like data driven investing and are willing to do the work, Portfolo123 provides all the information you need to construct and trade investment strategies. I've been a client for about 10 years and, for fundamental investing, I haven't found any site that comes close. You can write your own formulas to interpret the data, weight stocks in your portfolio, use your own buy and sell rules, trade weekly, monthly, or however often you think appropriate. You can test your strategies on data going back many years, and they provide articles and a forum for exchange of information to help you learn about factor investing and how to use their site. I wouldn't go anywhere else to manage my money.

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.

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.

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