How can we build trust, especially in polarized societies? We propose that exposure to broad financial markets—where individuals place their assets in the hands of large groups of unfamiliar agents who nonetheless have the incentive and ability to promote their interests—can contribute to generalized trust. In a randomized controlled trial, we encourage Israelis to hold or trade stocks for up to seven weeks. We find that participation in financial markets increases the probability of expressing generalized trust by about 6 percentage points, equivalent to a quarter of the control group mean. The effects seem to be driven by political partisans along the left–right spectrum in Israel, and are robust to negative price changes. Thus, trust is not only a cause but can also be an effect of participation in financial markets.