Couple reasons:

1) when the price has recently ripped, it attracts new retail who have no education on the asset and are not prepared to hold it at a loss

2) now that ETFs are holding, they have rebalancing requirements that may have a delayed effect on price. All the ETFs dumping on schedule at once would move the market

3) leverage trading is a battleground. Any sudden shot up or down is leveraged longs/shorts getting liquidated and needing to cover

4) there have been credible accusations in the past that large actors like Tether/Bitfinex are able to (and do) spoof the market with stablecoins, in which case, who knows exactly their short term goals, but I’m confident their long term goal is global adoption