As you stated, the simplest theory is the most likely. The simplest, most logical theory is they see tremendous opportunity at these levels and are buying as fast as they can. They have only one thing in mind, to make money off their investment.
Since they own so much and continue to buy more every chance they can, the only way for them to make money is for the company to be sold outright at some point in the future. To my knowledge they don't take companies private, they invest until they are sold. My guess is we will be sold in 1-3 years at substantially more than today's price after positive ph 3 results cause our price to approach triple digits. They aren't looking for returns measured in double digit percentages, they invest to make 5-10 baggers on their investments and SGEN will be no different IMO.
Thanks all for your thoughts on this board. As you know I don't post much and appreciate those who keep things civil with well reasoned support. SGEN currently is my biggest investment and I plan on adding a small amount to my holdings once cash becomes available in the next couple of weeks. Hopefully I don't have to pay too much more. GLTA.