The source is the Geron ballot that just came in the mail. It asks to approve an amendment to increase the aggregate number of shares of Common Stock by 5,000,000 shares. That's a of zeros and typical, seems like every bump up gets hit with a dilution.
You have the right ideas. The offering is also about equal to or less than a day's trading which will not be executed in just one day. Yet, it does reveal that something has already been financed by whoever the funds so generated go to. Who are these parties (may not be the sellers or are they)?