All bets are off
For weeks, despite volatile poll swings, the conventional wisdom held that once Britons went into polling places, they'd choose the perceived rational option: Stay with the safe option, remain in the EU.
On Thursday night, UK voters handed conventional wisdom a dose of reality about the global order.
In the US, there will be a lot of immediate talk about what this means for its big upcoming event: The 2016 presidential election.
More specifically, what does it mean for Donald Trump?
If there's one conclusion to draw from the Brexit result, it's that nationalist sentiments may not necessarily be visible to political elites but the right person, with the right cause, can easily bring them out.
"Populism is rising everywhere as people decide that government does not listen and does not care," veteran Republican pollster Frank Luntz told Business Insider.
"But this is even more significant, because Britain has never been the source of populist uprisings like this. If Britain can vote itself out of Europe, America can vote itself in for Trump."
In the UK, the "Remain" camp was the safe bet. The probability of Britain remaining in the EU, as late as Thursday morning, was 86%, according to Betfair.
In the US, the safe bet is Hillary Clinton. The presumptive Democratic presidential nominee has an increasingly gigantic lead over Trump in polls - much larger than the lead ever was for "Remain." Trump is running what increasingly appears to be a further sinking campaign.
The Brexit vote makes one thing clear: For the foreseeable future, all bets are off.
And this could foreshadow more political disruption in the coming months.
The vote "does really support the Eurosceptic movements across Europe: the National Front in France, the Five Star movement in Italy, the Alternatives for Deutschland," and more, said Ian Bremmer, the president of the geopolitical risk firm Eurasia Group.
To that end, Scotland's first minister announced early Friday that it sees its future with the EU, indicating that it could hold another referendum to potentially split from Britain. A far-right party in the Netherlands, meanwhile, called for its own EU referendum.
As Bremmer pointed out, there's no immediate direct conclusion to draw about its implications for the US.
Yet the parallels are there, on the surface: Trump is the US answer to the growing tide of populism and nationalism across the world.