While there are no restriction on how you can spend it, there are restrictions (conditions) if it you can even take it under the cares act. It must because of one of the 3 (I,II,III) conditions described in the act. You cannot just take a distribution under the CARES act for other reasons, such as investing - it must be corona virus-related in one of the three ways.
(A) CORONAVIRUS-RELATED DISTRIBUTION.—Except as provided in paragraph (2), the term “coronavirus-related distribution” means any distribution from an eligible retirement plan made—
(i) on or after January 1, 2020, and before December 31, 2020,
(ii) to an individual—
(I) who is diagnosed with the virus SARS–CoV–2 or with coronavirus disease 2019 (COVID–19) by a test approved by the Centers for Disease Control and Prevention,
(II) whose spouse or dependent (as defined in section 152 of the Internal Revenue Code of 1986) is diagnosed with such virus or disease by such a test, or
(III) who experiences adverse financial consequences as a result of being quarantined, being furloughed or laid off or having work hours reduced due to such virus or disease, being unable to work due to lack of child care due to such virus or disease, closing or reducing hours of a business owned or operated by the individual due to such virus or disease, or other factors as determined by the Secretary of the Treasury (or the Secretary's delegate).
You also must "certify" to the plan administrator that you fall under those conditions so that they will properly code the 1099-R so show that the 10% penalty is an exception.
(B) EMPLOYEE CERTIFICATION.—The administrator of an eligible retirement plan may rely on an employee’s certification that the employee satisfies the conditions of subparagraph (A)(ii) in determining whether any distribution is a coronavirus-related distribution.
