What events correspond to the recent peaks in the chart? It looks like the VC world was spooked around the start of December and nothing has changed its mind ever since.

Given these are startups, I would expect much of the information to be private, but it seems highly unlikely this is a complete black box.

Edit: The comments below raise good possibilities. My own (very naïve) research yielded that there was a sharp dip in the the overnight repurchase agreements at the start of December and a small rise a month later. I don't think this is the cause, and I'm probably biased by media narrative more than anything, but it might lead somewhere assuming there's a connection by way of the amount of easy money floating around. The EFF rate also dropped around 24th of July and hasn't gone back up [2].

[1] https://fred.stlouisfed.org/series/RPONTSYD [2] https://fred.stlouisfed.org/series/DFF