Pretty much a pattern if you'll ask me. Whenever there's high volatility you'd find that the fees surge upwards, soon as it stabilizes fees go down with it. Not really sure bout the nitty-gritty but I guess it has something to do with congestion of transaction within the network as it's expected that more and more people will buy and sell during these crunch times (correct me if I'm wrong with this). Add to this the expected surge of activity within the network courtesy of Ordinals and their shenanigans (which I am not really against since it's about time bitcoin gets its own NFT), and expect a pretty nasty increase in fees in the next months or so.