Portfolio123 is the best web-based resource for investors. It allows you to discover exciting new stock/ETF ideas, create investment strategies using ranking and screening, backtest them with realistic simulations, and implement them in real-time with advanced trading tools -- including seamless and commission-free trading across multiple accounts.
Portfolio123 (portfolio123.com) has 45 customer reviews on Five Star Index, with an average rating of 4.8 out of 5.
Also known as
portfolio123.com
Website
portfolio123.com
Category
Investments & Wealth
Location
Glenview, Illinois
Listed on Five Star Index
2026
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The company replied to 64% of reviews.
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Most recent review: April 2026.
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I started using portfolio123 around 19 years ago.
Simply the best product for quantitative stock analysis. No other come even close. The only solution you need for your stock investment assuming you have the time and desire to learn factor investing.
NH
Ned H.
An excellent resource for…
An excellent resource for evidence-based investment research. The features and functionality are outstanding.
WA
WalterW
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.
CH
Chaim
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.
GG
G G.
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.
AN
Andrew
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.
JA
James
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.
WZ
Wenzhang Z.
Toxic environment
Toxic environment that stigmatizes creative, productive, diverse critiques as so-called "unconstructive" and "repetitive" and condones toxic personal attacks.