I use a novel data set to investigate sustainable trading of Swiss retail investors.Based on an investor‘s past trading decisions in sustainable-labelled funds and bonds I gauge the sustainability preference of investors and identify sustainable investors. Then I analyze their stock purchases preferences and their investment performance. Investors with higher sustainability preference purchase stocks with higher ESG scores and lower CO2 emissions. They are more likely to purchase stocks in green industries and less likely to purchase stocks in brown industries. Finally, these investors show higher past investment return and lower investment volatility. Overall, the findings suggest that specially skilled investors engage in sustainable investing, after having experienced positive returns and that these investors do not hedge their stock ESG risk from brown stock investments but have consistent sustainability preferences across asset classes and industries.