I feel a better analogy is house purchasing. The same house can have different values for you and me because we value it based on our own needs and we have different needs. For AMRN's case, a buyer who owns a statin can value AMRN higher than another one without statin, because the two drug's sales are synergistic. Share price or market cap is a valuation "assessed" by the market (i.e., sell-side & buy-side analysts, institutional and individual shareholders) as a stand alone entity most times until rumor or news of otherwise strikes.