The article explores how firms choose the maturity of their risky debts to signal their quality to investors. When insiders have more information than investors, they issue securities that the market overvalues. Investors then try to figure out the insiders' information from the firm's financial structure. With low transaction costs, a firm's financial structure doesn't give a clear signal. But with higher costs, high-quality firms can effectively show their true quality. The ability to signal quality depends on the distribution of firms' quality and the costs of underwriting corporate debt.