Costar CSGP Institutional Ownership

Updated Oct 21, 2026

Costar Group, Inc. (NASDAQ:CSGP) was held by 750 institutional investors that filed 13F reports for the quarter ended June 30, 2026.

• Total shares held in Costar rose 2.00% from Q1 2026, while the number of holders fell 13.39% from Q2 2025.
• Among the 750 holders of Costar, 415 added to their positions, 256 reduced their stakes and 79 left their positions unchanged.
• Altogether, institutional holders owned 410.46Mn CSGP shares at the end of Q2 2026, up 8.04Mn from the prior quarter and down 2.72Mn from a year earlier.
• Vanguard Portfolio Management LLC held the largest position in CSGP at 37.91Mn shares as of June 30, 2026.
• Among existing holders, the largest additions to Costar in Q2 2026 came from AQR Capital Management LLC (+7.18Mn shares), BAMCO Inc (+5.31Mn shares), Federated Hermes, Inc. (+3.13Mn shares), JPMorgan Chase & Co (+3.09Mn shares) and Meritage Group LP (+2.07Mn shares).
• The largest position reductions in CSGP for Q2 2026 were by Principal Financial Group Inc (-13.91Mn shares), D. E. Shaw & Co., Inc. (-4.87Mn shares), Goldman Sachs Group Inc (-4.12Mn shares), Polen Capital Management LLC (-3.81Mn shares) and Mackenzie Financial Corp (-1.48Mn shares).
• According to Business Quant data, the leading holders of CSGP for Q2 2026 were Vanguard Portfolio Management LLC (37.91Mn shares), BlackRock, Inc. (33.81Mn shares), Vanguard Capital Management LLC (26.68Mn shares), BAMCO Inc (21.63Mn shares), State Street Corp (18.41Mn shares), Capital International Investors (16.64Mn shares), Baillie Gifford & Co (13.15Mn shares), Geode Capital Management, LLC (12.17Mn shares), Akre Capital Management LLC (11.7Mn shares) and Polen Capital Management LLC (8.76Mn shares).