CoStar Group, Inc.
US ˙ NasdaqGS ˙ US22160N1090

SecurityCSGP / CoStar Group, Inc.
InstitutionSummit Trail Advisors, Llc
Latest Disclosed Ownership23,785 shares
Latest Disclosed Value $ 959,487
Summit Trail Advisors, Llc reports 64.55% increase in ownership of CSGP / CoStar Group, Inc.

On May 12, 2026 - Summit Trail Advisors, Llc filed a 13F-HR form disclosing ownership of 23,785 shares of CoStar Group, Inc. (US:CSGP) valued at $959,487 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 14,455 shares of CoStar Group, Inc.. This represents a change in shares of 64.55% during the quarter. The current value of the position is $794,419 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-05-12 2026-03-31 13F COSTAR GROUP COM 22160N109 23,785 9,330 64.55 959 -1.24 0.0137
2026-02-17 2025-12-31 13F COSTAR GROUP COM 22160N109 14,455 1,581 12.28 972 -10.59 0.0168
2025-11-14 2025-09-30 13F COSTAR GROUP COM 22160N109 12,874 3,928 43.91 1,086 51.04 0.0150
2025-08-14 2025-06-30 13F COSTAR GROUP COM 22160N109 8,946 -340 -3.66 719 -2.18 0.0123
2025-04-28 2025-03-31 13F COSTAR GROUP COM 22160N109 9,286 2,197 30.99 736 44.97 0.0243
2025-01-29 2024-12-31 13F COSTAR GROUP COM 22160N109 7,089 559 8.56 508 3.05 0.0187
2024-11-12 2024-09-30 13F COSTAR GROUP COM 22160N109 6,530 3,367 106.45 493 110.26 0.0122
2024-08-13 2024-06-30 13F Costar Group Inc Com COM 22160N109 3,163 -333 -9.53 235 -30.56 0.0062
2024-04-23 2024-03-31 13F COSTAR GROUP COM 22160N109 3,496 3,496 338 0.0090
2024-02-06 2023-12-31 13F COSTAR GROUP COM 22160N109 0 -2,831 -100.00 0 -100.00
2023-10-30 2023-09-30 13F COSTAR GROUP COM 22160N109 2,831 399 16.41 218 0.46 0.0080
2023-07-25 2023-06-30 13F COSTAR GROUP COM 22160N109 2,432 2,432 216 0.0082
2021-02-16 2020-12-31 13F Altria Group Inc Com Equity 22160N109 0 -10,911 -100.00 0 -100.00
2020-11-16 2020-09-30 13F Altria Group Inc Com Equity 22160N109 10,911 10,911 431 0.0834
2018-08-10 2018-06-30 13F COSTAR GROUP INC COM EQUITY 22160N109 0 -105,838 -100.00 0 -100.00
2018-05-21 2018-03-31 13F COSTAR GROUP INC COM EQUITY 22160N109 105,838 105,339 21,110.02 106 -38.73 0.0165
2018-02-14 2017-12-31 13F COSUMMIT TRAILR GROUP INC COM EQUITY 22160N109 499 499 173 0.0218
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.