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.

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.

I started using portfolio123 around 19… 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.

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.

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