Apparently along with Swartz there are many here that own millions of shares. I don't think you will be able to determine the sell points of a great multitute of investors with varying reasons for selling or holding. All you can do is watch the level II try to get a feel of the bid and ask pressures, keep abreast of news hopefully they will become more forthcoming with contract amounts. Keep in mind that this stock will probably be very volitile for a while with momenteum investors joining the fray, Again, because of that it will be even harder to anticipate where the S/P will end up.

Good luck

P.S. you made about 4, and 8 X your investment, You are one of those smart investors.