Ann: Vorago Technologies Collaboration, page-162

People taking profits most likely. Everyone has their targets. If someone makes 25% and is happy with that, they can sell and reinvest elsewhere (or buy the next dip). I did it earlier at 35c (before today's announcement unfortunately) to cover my initial investment and am now free-holding.
There's still a high degree of risk despite being significantly derisked lately (from a cash funding POV and legitimisation that the tech works). We need sales traction so I can't blame people selling. IMHO though, I do believe the trend will continue upwards in both the short term with a few more announcements yet to come (chip testing + Tensor) and long term (contracts/partnerships with $$$ attached).