We study the impact of a national road construction program that brought access to previouslyunconnected pincodes in India, on stock market participation. Using a unique dataset on thetrading behavior of over 13 million individuals, we find that construction of new feeder roads to apincode increases the number of new investors by 6.8% and the number of trades by 7.9% and the effects are larger for rural vs. urban areas and for pincodes at intermediate levels of development. The stock market participation effects are largely driven by new bank branch openings within three years of the road construction suggesting a financial inclusion channel. We also see greater effects for pincodes more distant from the nearest big city, greater portfolio diversification, and increased trading in companies located farther away, all suggesting an information channel.