Populism has been on the rise, posing a threat to liberal democracy. Existing evidence suggests that globalization, economic shocks, and concerns over cultural change increase support for populist agendas. Yet less is known about interventions that can empower individuals to critically evaluate populist messaging. We argue that tailored exposure to financial markets can reduce support for populist policies because it can encourage learning about the gains of economic complementarity and the costs of nativism and isolationism. We test this argument with an RCT implemented in the run-up to the Brexit referendum. We randomly assigned British citizens to hold and trade complementary financial assets from the UK, EU and the US for six weeks. We show that this intervention increased citizens’ willingness to vote to remain in the European Union during the Brexit Referendum, and particularly so when exposed to companies that exemplify EU-UK economic complementarity. Countering populist narratives, treated participants instead came to associate the EU with economic prosperity, rather than a threat to their cultural identity or a waste of money. Overall, the effects are stronger among swing participants and those originally more open to a European cultural identity.