ems v emsob

I have been holding and tracking (and praying for!) EMS over the last few years now. Great story. Incredible potential with ethical investment thrown in for good measure. Cracking.

I have recently rebalanced my holdings slightly out of EMS and into EMSOB on the grounds that I believe we're looking at a binary trading event here:

1. Given the timing of malaria season and the on-going trials, if we're going to get up then we're going to have to do so in the next 6 months, e.g. before EMSOB expiry.

0. Failure to get to the monetisation / big investor stage by Jun-11 will not only make the EMSOB worthless but also smash EMS give the likely funding pressure.

Is this thinking correct?
If not, why not?
If so, is liquidity the only factor that would explain the low pricing of the options relative to EMS?

Happy to hear any comments on my thinking and listen to any holes there might be in my rationale.