I don't have time to read it right now, but it looks like it is not an acquisition but a conversion of preferred shares they purchased last year for $2.6M. They may have been able to convert early because of the secondary that just completed.
no news - the stake is down from 14% reported one year ago. They saved the company from bankruptcy one year ago with a small seven digit investment and got 14% of the company in exchange. The stake has been diluted to 9.4% due to PLUG issuing more and more shares.