This is a simple mean-reversion bet. As you can see, it's rare for the index to go more than 800 days without revisiting this long-term trendline. There's nothing special about the trendline, it's just a moderately aggressive rate of price appreciation that fits the log chart pretty well.
I would trade this idea by purchasing a SPY 455 Put with April 2025 expiration.
This has not mean-reverted as quickly as I had hoped. I'm now targeting January 2026 insted of April 2025. I'm also focusing on individual stocks that I think are extremely overbought, including LYV, COST, and SPOT.