U.K. voters backed a "Brexit" from the European Union early Friday — a move which shocked markets and triggered strong reactions online.
The Twitter hashtag #Brexit topped the list of trending topics. Nigel Farage, a key player in the "Leave" movement, declared the U.K. had its "Independence Day."
Some drew parallels to the populist nature of the Brexit campaign and the looming U.S. presidential election.
@RichardHaass: Anti-establishment, populist, nationalist views leading to #Brexit parallels rise of Sanders & Trump in US & suggests Nov outcome uncertain
@joshrogin: Of course Putin is happy about #Brexit. Undermining the integrity and success of the EU is a key project for him.
@BobRae48: Conservative supporters of #Brexit completely under-estimate deeply disruptive effect of this vote and real harm to follow
@Ted_Scheinman: "...and in the end, Britain, which had colonized the world, destroyed itself in fantasies that it was being colonized in turn" — historians.
Others made jokes — some darker than others.
@cnbcSri: Sterling gets trashed after #Brexit outcome but (cheeky) British wit shines through #EUref #FX $GBPUSD $EUR
David Rothkopf, CEO and editor of FP Group, which publishes Foreign Policy magazine, referenced the plummeting of the British pound.
The official Twitter account for the popular political drama "House of Cards" a gif of the show's devious protagonist, Frank Underwood.
Others expressed dismay.
@NewmanDipFa: I'm so angry. A generation given everything: Free education, golden pensions, social mobility have voted to strip my generation's future.
Former Oasis singer Liam Gallagher also weighed in Friday morning.