The executive order prohibits all U.S. investors (institutional and retail investors alike) from purchasing or investing in securities of companies identified by the U.S. government as "Communist Chinese military companies".[1][2] A "Communist Chinese military company" is any company that the U.S. Department of Defense has identified pursuant to Section 1237 of the National Defense Authorization Act for Fiscal Year 1999. The prohibition came into effect on January 11, 2021.[3] On December 28, 2020, guidance on the executive order was published clarifying that the order included subsidiaries of the relevant companies.[4][5] On January 13, 2021, the executive order was strengthened with an amended directive that mandated divestment by November 11, 2021.[6] Jan 2021