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.

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.

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.

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.