It depends heavily on the culture at the startup. As an employee at a startup, it is very rare to really be exposed to what it means to run a startup. Most of the time you'll just be a code monkey, spending 60 hours in front of a computer and watching the CEO come and go without really knowing much about what they do.

Some companies try to be very transparent, keep everybody up-to-date when it comes to deals, negotiations, stuff like that. In such an environment yes you can gather some good knowledge.