A long post and I never answered your question. When a major takes out an exploration company, it typically offers cash and/or shares in the major for 100% of the takeover target. The offer is either supported or opposed by the management of the takeover target, as well as analyzed by an independent company that advises the shareholders to support or oppose the offer. The offer can be accepted outright or sweetened, or a rival bidder can join the discussion. Ultimately, shareholders vote to accept or reject the final offer, generally one share-one vote. So the major shareholders determine whether or not the deal gets done. As a result, smaller shareholders are along for the ride, because their fewer shares/votes can't swing the process. The price of the buyout is determined without the smaller shareholders having to decide when to sell. Hope that helps.
RTR