Values handshakes are a proposed form of trade between superintelligences. From The Hour I First Believed by Scott Alexander:
Suppose that humans make an AI which wants to convert the universe into paperclips. And suppose that aliens in the Andromeda Galaxy make an AI which wants to convert the universe into thumbtacks.
When they meet in the middle, they might be tempted to fight for the fate of the galaxy. But this has many disadvantages. First, there’s the usual risk of losing and being wiped out completely. Second, there’s the usual deadweight loss of war, devoting resources to military buildup instead of paperclip production or whatever. Third, there’s the risk of a Pyrrhic victory that leaves you weakened and easy prey for some third party. Fourth, nobody knows what kind of scorched-earth strategy a losing superintelligence might be able to use to thwart its conqueror, but it could potentially be really bad – eg initiating vacuum collapse and destroying the universe. Also, since both parties would have superintelligent prediction abilities, they might both know who would win the war and how before actually fighting. This would make the fighting redundant and kind of stupid.