Actually, yes, both are substantially different from Bitcoin. Both stock and futures contracts carry legal weight -- basically they are contracts and their value is ultimately a result of their legal meaning, despite all the speculators you hear about. From time to time you can see news about shareholder lawsuits or elections of corporate leadership. Companies often use futures contracts to reduce the risk of buying raw materials (fuel, food, etc.) for their operations.
With Bitcoin you have no legal guarantees at all.