We test whether investor mood affects trading with data on all stock market transactions in Finland, utilizing variation in daylight and local weather. We find some evidence that environmental mood variables (local weather, length of day, daylight saving and lunar phase) affect investors'...

During the COVID-19 pandemic, many new individual investors globally entered the stock markets, often pursuing speculative investment strategies that resemble gambling. A concern is that trading as a form of gambling can become addictive for some people, as documented by several recent studies...