You have a valid concern and it is reasonable to feel as you do. I was surprised that 3M+ shares had sold as you say. People sell for many reasons and I think most of these shares come from those who over-loaded at 25 cents or less. You must have heard the expression, " back up the truck "? Some people do ( the lucky ones). At $1 they can sell enough shares to lighten their portfolio to a core position and ride them free. Same reason many warrant holders did. So the fact this many shares traded doesn't bother me. I would have thought they would wait for the purity results. The chances of them being good are high and the expectation of the share price going to $1.50 is a reasonable expectation. They are removing some of the risk and feel more comfortable doing it. I am sure they have another batch to sell if it hits $1.50. So I see this as normal.
I'm riding the stock until the purity results come out. It has taken more time than expected but that is a common event. Staying on a time schedule is difficult. Something unexpected seems to show up that we do not foresee. If you have a problem with how many shares you have and lightening up makes you feel better, that may be the right move for you. Sleeping well at night is important.