What Happened to the Hype Stocks from 2022? Why Did the Sentiment Shift So Drastically now again?

I wasn’t actively investing back in 2021–2022, but looking at the charts in hindsight, the sentiment shift around many hype stocks seems almost inexplicable. Companies like PLTR (and many others that SPACed around the timeframe I am talking about) had insane valuations during the peak, then crashed to what seemed like reasonable levels where they stayed a while, and now valuations are back to being sky-high again.

What confuses me is that fundamentally, a lot of these companies have been improving steadily—their stocks stayed flat for a while, even in a bull market for the rest of the market, nothing major changed for them in autumn 2024, yet suddenly most of them started gaining traction again. Even before the election and it is also not like Trump changed many things for them. Some of them weren’t even that affected by interest rates or the overall US economy, so what caused this sudden resurgence?

Was the 2021–2022 crash purely a sentiment shift, and are we now back to another euphoric phase that will be over? It seems as if a lot of investors seemed extremely bullish back then, but after the crash, many just disappeared for a while. Is this just another cycle of speculation, or is there something more to it now?

I’d love to jump in when valuations get reasonable again, but I’m sceptical that will happen anytime soon. Would appreciate insights from those who were active back then—what drove these swings, and do you think we’ll see another opportunity like the 2022-bear-market levels again? I would be content with last year's valuations.