This article documents a link between trading and diversification by using detailed trading records from a Swedish discount broker matched with individual tax records. Diversification is measured by the investors’ stake size, defined as the fraction of their risky financial wealth invested in individual stocks through the broker under study. High-stake investors have concentrated portfolios, trade more, and achieve lower trading performance. They share several features with those who trade excessively, namely lower income, wealth, age, and education, suggesting that they lack investment expertise. The results directly imply that trading losses in the cross-section are mainly borne by those who can least afford them.

We survey a large sample of Swedish households and connect the responses to administrative data to relate pro-environmental attitudes and values to actual investment decisions. Pro-environment households are not more likely to hold pro-environment portfolios. This results from financial disengagement: they are less likely to own stocks, check pension balances, or make green active retirement planning choices. Green financial engagement is stronger in settings where financial literacy is higher or where informational hurdles are lower. Informational barriers appear to prevent financial market prices and returns from fully reflecting household environmental preferences.