42% buyers of institutions opening or closing positions this quarter
51 more exits than new buyers, ownership fell 78.02 percentage points vs the prior quarter, and 1 well-known fund manager in the top 25.
42% buyers of institutions opening or closing positions this quarter
114.2% institutional ownership
AKRE CAPITAL MANAGEMENT portfolio allocation
Institutional ownership vs Real Estate - Services peers
1 Form 4 filings β executives buying or selling their own stock
Latest positioning in CSGP across 13F flow, ownership shift, marquee holders, and holder-count growth.
Ranked by reported Q1 2026 13F market value
Share of total reported institutional value in CSGP held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | VANGUARD PORTFOLIO MANAGEMENT LLC | 38.2M | $1.54B | β | 9.021% | 0.08% |
| 2 | BlackRock, Inc. | 33.8M | $1.36B | -0.5% | 7.977% | 0.02% |
| 3 | VANGUARD CAPITAL MANAGEMENT LLC | 27.4M | $1.11B | β | 6.471% | 0.03% |
| 4 | STATE STREET CORP | 18.7M | $752.4M | +0.1% | 4.401% | 0.03% |
| 5 | PRINCIPAL FINANCIAL GROUP INC | 17.7M | $713.9M | +0.7% | 4.175% | 0.38% |
| 6 | BAMCO INC /NY/ | 16.3M | $658.1M | -16.3% | 3.849% | 1.99% |
| 7 | Capital International Investors | 15.5M | $625.8M | +43.1% | 3.660% | 0.15% |
| 8 | BAILLIE GIFFORD & CO | 13.6M | $549.1M | +5.2% | 3.211% | 0.56% |
| 9 | POLEN CAPITAL MANAGEMENT LLC | 12.6M | $507.1M | +157.0% | 2.966% | 3.51% |
| 10 | GEODE CAPITAL MANAGEMENT, LLC | 12.4M | $500.4M | +2.2% | 2.937% | 0.03% |
| 11 | AKRE CAPITAL MANAGEMENT LLC | 10.3M | $417.4M | +7.6% | 2.442% | 6.80% |
| 12 | GOLDMAN SACHS GROUP INC | 9.3M | $373.3M | +146.7% | 2.184% | 0.04% |
| 13 | JANUS HENDERSON GROUP PLC | 7.7M | $311.6M | +3.4% | 1.823% | 0.15% |
| 14 | Invesco Ltd. | 7.1M | $287.9M | +32.5% | 1.684% | 0.04% |
| 15 | D. E. Shaw & Co., Inc. | 5.9M | $238.4M | +552.7% | 1.394% | 0.14% |
| 16 | MORGAN STANLEY | 5.4M | $218.3M | +2.3% | 1.277% | 0.01% |
| 17 | Capital Research Global Investors | 4.4M | $176.4M | -21.4% | 1.032% | 0.03% |
| 18 | BANK OF AMERICA CORP /DE/ | 3.6M | $143.9M | +1.8% | 0.842% | 0.01% |
| 19 | NORTHERN TRUST CORP | 3.4M | $138.5M | -1.0% | 0.810% | 0.02% |
| 20 | Meritage Group LP | 3.3M | $134.3M | β | 0.785% | 5.07% |
| 21 | Amundi | 3.3M | $132.3M | -20.3% | 0.774% | 0.04% |
| 22 | Legal & General Group Plc | 3.0M | $122.0M | +5.7% | 0.714% | 0.03% |
| 23 | CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 2.9M | $115.9M | +7.9% | 0.678% | 0.02% |
| 24 | FMR LLC | 2.8M | $114.2M | +135.5% | 0.668% | 0.01% |
| 25 | Ensign Peak Advisors, Inc | 2.7M | $110.3M | +372.8% | 0.645% | 0.21% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). β% of Fundβ shows how much of that investorβs total 13F portfolio is invested in CSGP β a direct measure of their conviction.
Filings activity in CSGP during Q1 2026, grouped by how each filer changed its position.
Institutions that opened a new CSGP position in Q1 2026
Institutions that fully closed their CSGP position in Q1 2026
8 quarters of 13F filings Β· Ξ columns show change vs prior quarter
| Quarter | Inst. Holders | Ξ Holders | Ownership % | Ξ Ownership | Total 13F Value | Ξ Value |
|---|---|---|---|---|---|---|
| Q1 2026 | 773 | 6.2% | 114.22% | 78.02 pp | $15.81B | 40% |
| Q4 2025 | 824 | 5.0% | 192.24% | 7.75 pp | $26.50B | 21% |
| Q3 2025 | 867 | +1.9% | 199.99% | +0.00 pp | $33.63B | +2.7% |
| Q2 2025 | 851 | +2.3% | 199.99% | +0.00 pp | $32.73B | 58% |
| Q1 2025 | 832 | +8.5% | 199.99% | +1.87 pp | $78.35B | +187% |
| Q4 2024 | 767 | +3.6% | 198.12% | 1.87 pp | $27.31B | 83% |
| Q3 2024 | 740 | +0.4% | 199.99% | +0.00 pp | $161.34B | +206% |
| Q2 2024 | 737 | β | 199.99% | β | $52.77B | β |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Ξ columns compare to the immediately prior filed quarter.
Latest Form 4 transactions by company officers and directors. Insider buys are widely viewed as the highest-conviction signal because executives are risking personal capital.
| Date | Insider | Action | Shares | Price | Value |
|---|---|---|---|---|---|
| May 1, 2026 | FLORANCE ANDREW C | Buy | 68K | $35.17 | $2.4M |
Quick answers to the most common questions about buying CSGP stock.
Based on Q1 2026 13F filings, institutional ownership of CoStar Group, Inc. stands at 114.2%, held across 773 reporting institutions.
VANGUARD PORTFOLIO MANAGEMENT LLC is the largest reported institutional holder of CSGP, with approximately 38,234,133 shares worth $1.54B as of Q1 2026.
Yes β 1 widely-followed marquee investor appear among the top 25 institutional holders of CSGP, including AKRE CAPITAL MANAGEMENT LLC.
Our composite Smart Money Score for CSGP is 29 out of 100 (Bearish). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
138 institutions opened new positions in CSGP during Q1 2026, while 189 fully exited. 116 added to existing positions and 513 trimmed.
CSGP institutional ownership fell by 78.02 percentage points quarter-over-quarter, with a net change of -51 holders.
The top 10 institutions account for 52.6% of all reported 13F value in CSGP, and the top 25 account for 71.8%.
All data is sourced from SEC Form 13F filings, which institutional investment managers with at least $100M in assets are required to file each quarter. We process every 13F filing from EDGAR and recompute the aggregates after each cycle. Insider transactions are sourced from Form 4 filings.