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.

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.

If you want to have quality data for… If you want to have quality data for everything from fundamental analysis to advanced machine learning there is no better place. Personally, I have used it for advanced machine learning. The downloads and tools are perfect for this. It can give you excess returns with everything from simple regressions to XGBoost and neural-nets. I think if you like machine learning there is no other place to be. It has worked and continues to work for me. I have been a member for over 10 years. Also keeping track of your investing is easier and better than any other site I have looked at. Automatically editing your buy and sell prices, Giving equity curves, Sharpe ratios, alpha etc Put more simply it will make you money. This is true for a lot of different investment styles (mine being machine learning). And you can keep track of what is working best for you over time. If I could give it a higher rating, I would (which serves to illustrate I was never all that good at fractions in school). But P123 is a useful tool even for me. I recommend that you try it. I do not think you will regret it—assuming you like quality data to use for your own investing methods.

Highly recommended They make a great product and offer a good service. They are responsive. It takes time to learn their tools and how to navigate their website which is no different than any other comparable site except that you are doing far less coding from scratch and more actual thinking and developing trading models.

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.