The amateur crypto analysis are saying the pump was triggered by CME futures expiring so putting bitcoin back into hands of those who put their money into those before the run up in January.
But on the other hand others who are experts are saying those futures were too small to cause the price to tumble to $6k in the first place which would negate what those analysis said caused the bull run yesterday.
https://cryptobriefing.com/bitcoin-futures-small-btc-price