Roughly 10× or more, depending on the exact month — QQQ compounded at ~17-18% annually through the 2010s and 2020s. Use the Time Machine to replay the exact monthly path, including the drawdowns you would have had to sit through, and compare it against the S&P 500 over the same window.

Yes. The tool uses monthly adjusted close prices, which incorporate reinvested dividends and stock splits. That makes it a total-return simulation, not just a price chart.

If you pick a month before the fund existed, the simulation starts at the fund's first month of available data. The result header always shows the actual period simulated.

No — it replays what already happened. Past performance does not guarantee future results; spectacular historical runs (and crashes) may not repeat. The tool exists to build intuition about compounding, volatility, and holding through drawdowns.