UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.F. 20549 SCHEDULE 13G PROS HOLDINGS, INC. Common Stock 74346Y103 Item 1. a. PROS Holdings, Inc. b. 3100 Main Street Suite 900 Houston, TX 77002 Item 2. a. D.F. Dent & Company, Inc. b. 400 East Pratt Street, 7th Floor Baltimore, Maryland 21202 c. Incorporated in the State of Maryland d. Common stock e. 74346Y103 Item 3. Investment adviser registered under section 203 of the Investment Advisers Act of 1940 Item 4. a. 30,389,000 b. 5.20% c. 1. 1,580,150 2. 0 3. 1,580,150 4. Item 5. N/A Item 6. N/A Item 7. N/A Item 8. N/A Item 9. N/A