Item 13. (b)

CERTIFICATION UNDER SECTION 906 OF SARBANES-OXLEY ACT OF 2002
Name of Issuer: T. Rowe Price QM U.S. Small-Cap Growth Equity Fund
In connection with the Report on Form N-CSR for the above named Issuer, the undersigned hereby certifies, to the best of his knowledge, that:
1.	The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934;
2.	The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Issuer.

Date: August 16, 2019	/s/ David Oestreicher
	David Oestreicher
	Principal Executive Officer
Date: August 16, 2019	/s/ Catherine D. Mathews
	Catherine D. Mathews
	Principal Financial Officer