AbstractCompanies use trademarks to protect their brands from outright imitation or competition by confusingly similar brands. However, publication of trademark applications by the trademark office discloses strategic information about a firm's future products and planned market entry. This creates a trade‐off between legal protection for new brands and inadvertent information disclosure. We analyze the trade‐off through the lens of “submarine trademarks” in the United States—submarine trademarks are trademarks whose publication and hence disclosure to the public are strategically delayed. We provide the first systematic evidence of submarine trademarks and explore their effectiveness in reducing the disclosure of information, their determinants, and their blocking effect on third‐party trademark filings. We also provide evidence on the effect of trademark disclosure on third‐party trademark filings.