What do shareholders contribute to the financing of an enterprise? What is the ratio between the dividends distributed and the subscriptions of shares in cash? What do public offerings and flotations on the stock exchange change? A systematic study of the subscriptions of joint stock companies operating 150 industrial firms with registered offices in the district of Lyon during the period between 1921 and 1953 provides new answers to these questions. The results are strongly dependent on economic trends: public offerings are only possible in booming phases and are then, like in the 1920s, able to contribute to the spectacular growth of some enterprises. The ensuing flotation on the stock exchange is mostly dedicated more to increasing the liquidity of the capital for the new shareholders than it is to bringing in new capital.