I really like your recreation of the monkey experiment. It shows the enormous deviation in returns in such a short period of time. (And the recent bull trend, every portfolio has positive returns?!)

I'm not a fan of market timing, especially with backtesting. At first glance, it always seems that a 'golden rule' or 'perfect trading strategy' exists. But when you backtest on a different time period, it suddenly doesn't work. However, I'm often tempted to try to time the market, so every once in a while I like to go back to Vanguards investing guide: https://personal.vanguard.com/us/insights/investingtruths/investing-truth-about-emotion
If you play around with the interactive chart you can see that small changes have a big effect and that overall, it's hard to beat the market.

Don't think that I didn't like your project though! Love it, just don't like market timing. ;)