Many people in this community have investments heavily concentrated in employer or founder stock, and face diversification trade-offs: tax drag, risk vs return.

While there's a number of investment portfolio and retirement simulators out there, surprisingly, I couldn't find any simulators that help with this common scenario, so I built one that helps explore those trade‑offs. You plug in your position, timeline, and taxes, and it creates a monte carlo simulation of how different sell‑down schedules might have played out using historical data and gives you visualizations for outcomes at different diversification rates, an efficient frontier chart (return/risk), tax drag, etc.

It's a labor of love: local and private, no monetization, no overselling of capabilities. Just hoping it helps other folks. I had a lot of fun diving into it and trying hard to get the details right, but I'm not a PhD in financial simulation so hit me up if I got something wrong (or right!), happy to fix it or add meaningful improvements.