I built ClosingBell Live — the desktop version of the original ClosingBell iOS app — this summer, and I've been rolling it out slowly to some of the users. I wanted to focus on the trading activity, as I felt that was the most interesting aspect of the product. So here is the MVP in all its glory. It reveals what thousands of stock traders are buying, selling, and holding in their portfolios. Flip a switch, and it reveals the moves of only the profitable traders. Why would anyone contribute to the data set? Because it operates on a give-to-get model. If you participate (connect a brokerage account and trade at least 3 stocks every 7 days), you'll get upgraded for free. If you don't want to participate, you can pay to upgrade. Ultimately, I'd like to expand the feature set to include more granular filters on the traders themselves. Alpha, beta, sharpe, location, occupation, etc. It's like a stock screener, but on the traders — not the underlying assets. If you want to test the subscription, use code PRODUCTHUNT for 100% off the first month.