It was a cross trade IMO.. MMs were moving shares from one account to another.
When you want in BIG, the best thing to do is contact an MM directly and see if they can help you get a block. If they think they can make a big score on the deal they will work the stock in your favor by calling around for shares and working the tape.... Im not 100% sure this is what happened, but it could be...
Ive seen these types of trades many times and it often happens before a big rise.. and this one sure looks like its headed up