CoStar Group, Inc.
MX ˙ BMV ˙ US22160N1090
DETTE SYMBOL ER IKKE LÆNGERE AKTIVT
SecurityMX:CSGP / CoStar Group, Inc.
InstitutionWalleye Trading LLC
Latest Disclosed Ownership72,509 shares
Latest Disclosed Value $ 2,925,013
Walleye Trading LLC ownership in CSGP / CoStar Group, Inc.

On May 8, 2026 - Walleye Trading LLC filed a 13F-HR form disclosing ownership of 72,509 shares of CoStar Group, Inc. (MX:CSGP) valued at $2,925,013 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 11,991 shares of CoStar Group, Inc.. This represents a change in shares of 504.70% during the quarter.

Walleye Trading LLC has a history of taking positions in derivatives of the underlying security (CSGP) in the form of stock options. The firm currently holds call options representing 29,500 of underlying shares valued at $1,190,030 USD and put options representing 3,100 of underlying shares valued at $125,054 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

MX:CSGP / CoStar Group, Inc. Historical Put/Call Ratio
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)
2026-05-08 2026-03-31 13F COSTAR GROUP COM 22160N109 72,509 60,518 504.70 2,925 262.90 0.0049
2026-02-13 2025-12-31 13F COSTAR GROUP COM 22160N109 11,991 3,203 36.45 806 8.77 0.0011
2025-11-14 2025-09-30 13F COSTAR GROUP COM 22160N109 8,788 8,788 741 0.0011
2024-11-14 2024-09-30 13F COSTAR GROUP COM 22160N109 0 -10,880 -100.00 0 -100.00
2024-08-14 2024-06-30 13F COSTAR GROUP COM 22160N109 10,880 10,880 807 0.0019
2024-05-15 2024-03-31 13F COSTAR GROUP COM 22160N109 0 -13,099 -100.00 0 -100.00
2024-02-14 2023-12-31 13F COSTAR GROUP COM 22160N109 13,099 13,099 1,145 0.0025
2022-05-16 2022-03-31 13F COSTAR GROUP COM 22160N109 0 -1,512 -100.00 0 -100.00
2022-02-14 2021-12-31 13F COSTAR GROUP COM 22160N109 1,512 1,512 119 0.0004
2021-11-15 2021-09-30 13F COSTAR GROUP COM 22160N109 0 -12,262 -100.00 0 -100.00
2021-08-16 2021-06-30 13F COSTAR GROUP COM 22160N109 12,262 12,262 1,016 0.0040
2021-02-16 2020-12-31 13F COSTAR GROUP COM 22160N109 0 -301 -100.00 0 -100.00
2020-11-16 2020-09-30 13F COSTAR GROUP COM 22160N109 301 -486 -61.75 255 -54.38 0.0014
2020-08-14 2020-06-30 13F COSTAR GROUP COM 22160N109 787 -21 -2.60 559 17.93 0.0036
2020-05-15 2020-03-31 13F COSTAR GROUP COM 22160N109 808 808 2.67 474 -15.21 0.0037
2020-02-14 2019-12-31 13F COSTAR GROUP COM 22160N109 0 -32 -100.00 0 -100.00
2019-11-14 2019-09-30 13F COSTAR GROUP COM 22160N109 32 32 19 0.0002
2018-11-14 2018-09-30 13F COSTAR GROUP COM 22160N109 0 -1,455 -100.00 0 -100.00
2018-08-14 2018-06-30 13F COSTAR GROUP COM 22160N109 1,455 831 133.17 600 165.49 0.0032
2018-05-15 2018-03-31 13F COSTAR GROUP COM 22160N109 624 624 226 0.0013
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-08 2026-03-31 13F COSTAR GROUP COM Call 29,500 -47.04 1,190 -68.22 n/a n/a n/a
2026-02-13 2025-12-31 13F COSTAR GROUP COM Call 55,700 50.95 3,745 20.30 n/a n/a n/a
2025-11-14 2025-09-30 13F COSTAR GROUP COM Call 36,900 -14.58 3,113 -10.37 n/a n/a n/a
2025-08-13 2025-06-30 13F COSTAR GROUP COM Call 43,200 -24.61 3,473 -23.49 n/a n/a n/a
2025-05-14 2025-03-31 13F COSTAR GROUP COM Call 57,300 -23.09 4,540 -14.89 n/a n/a n/a
2025-02-13 2024-12-31 13F COSTAR GROUP COM Call 74,500 101.35 5,333 91.08 n/a n/a n/a
2024-11-14 2024-09-30 13F COSTAR GROUP COM Call 37,000 -17.96 2,791 -16.51 n/a n/a n/a
2024-08-14 2024-06-30 13F COSTAR GROUP COM Call 45,100 -9.98 3,344 -30.92 n/a n/a n/a
2024-05-15 2024-03-31 13F COSTAR GROUP COM Call 50,100 43.14 4,840 58.24 n/a n/a n/a
2024-02-14 2023-12-31 13F COSTAR GROUP COM Call 35,000 -54.95 3,059 -48.81 n/a n/a n/a
2023-11-21 2023-09-30 13F/A COSTAR GROUP COM Call 77,700 -11.10 5,974 -23.19 n/a n/a n/a
2023-11-14 2023-09-30 13F COSTAR GROUP COM Call 77,700 5,974 n/a n/a n/a
2023-08-14 2023-06-30 13F COSTAR GROUP COM Call 87,400 -25.43 7,779 -3.61 n/a n/a n/a
2023-05-15 2023-03-31 13F COSTAR GROUP COM Call 117,200 11.51 8,069 -0.65 n/a n/a n/a
2023-02-14 2022-12-31 13F COSTAR GROUP COM Call 105,100 26.47 8,122 40.32 n/a n/a n/a
2022-11-14 2022-09-30 13F COSTAR GROUP COM Call 83,100 83.04 5,788 111.01 n/a n/a n/a
2022-08-08 2022-06-30 13F COSTAR GROUP COM Call 45,400 -8.47 2,743 -16.98 n/a n/a n/a
2022-05-16 2022-03-31 13F COSTAR GROUP COM Call 49,600 785.71 3,304 645.82 n/a n/a n/a
2022-02-14 2021-12-31 13F COSTAR GROUP COM Call 5,600 443 n/a n/a n/a
2021-11-15 2021-09-30 13F COSTAR GROUP COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2021-08-16 2021-06-30 13F COSTAR GROUP COM Call 3,000 900.00 248 0.40 n/a n/a n/a
2021-05-17 2021-03-31 13F COSTAR GROUP COM Call 300 -90.00 247 -0.40 n/a n/a n/a
2020-11-16 2020-09-30 13F COSTAR GROUP COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2020-08-14 2020-06-30 13F COSTAR GROUP COM Call 500 0.00 355 20.75 n/a n/a n/a
2020-05-15 2020-03-31 13F COSTAR GROUP COM Call 500 0.00 294 -17.18 n/a n/a n/a
2020-02-14 2019-12-31 13F COSTAR GROUP COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2019-11-14 2019-09-30 13F COSTAR GROUP COM Call 300 178 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-08 2026-03-31 13F COSTAR GROUP COM Put 3,100 -93.19 125 -95.91 n/a n/a n/a
2026-02-13 2025-12-31 13F COSTAR GROUP COM Put 45,500 -16.36 3,059 -33.34 n/a n/a n/a
2025-11-14 2025-09-30 13F COSTAR GROUP COM Put 54,400 151.85 4,590 164.34 n/a n/a n/a
2025-08-13 2025-06-30 13F COSTAR GROUP COM Put 21,600 40.26 1,737 42.30 n/a n/a n/a
2025-05-14 2025-03-31 13F COSTAR GROUP COM Put 15,400 -60.21 1,220 -55.96 n/a n/a n/a
2025-02-13 2024-12-31 13F COSTAR GROUP COM Put 38,700 225.21 2,771 208.81 n/a n/a n/a
2024-11-14 2024-09-30 13F COSTAR GROUP COM Put 11,900 -44.13 898 -43.19 n/a n/a n/a
2024-08-14 2024-06-30 13F COSTAR GROUP COM Put 21,300 -35.06 1,579 -50.16 n/a n/a n/a
2024-05-15 2024-03-31 13F COSTAR GROUP COM Put 32,800 8.97 3,168 20.46 n/a n/a n/a
2024-02-14 2023-12-31 13F COSTAR GROUP COM Put 30,100 -10.15 2,630 2.14 n/a n/a n/a
2023-11-21 2023-09-30 13F/A COSTAR GROUP COM Put 33,500 340.79 2,576 280.92 n/a n/a n/a
2023-11-14 2023-09-30 13F COSTAR GROUP COM Put 33,500 2,576 n/a n/a n/a
2023-08-14 2023-06-30 13F COSTAR GROUP COM Put 7,600 -13.64 676 11.74 n/a n/a n/a
2023-05-15 2023-03-31 13F COSTAR GROUP COM Put 8,800 -77.49 606 -79.97 n/a n/a n/a
2023-02-14 2022-12-31 13F COSTAR GROUP COM Put 39,100 303.09 3,022 346.89 n/a n/a n/a
2022-11-14 2022-09-30 13F COSTAR GROUP COM Put 9,700 3,133.33 676 3,655.56 n/a n/a n/a
2022-08-08 2022-06-30 13F COSTAR GROUP COM Put 300 -92.11 18 -92.89 n/a n/a n/a
2022-05-16 2022-03-31 13F COSTAR GROUP COM Put 3,800 52.00 253 27.78 n/a n/a n/a
2022-02-14 2021-12-31 13F COSTAR GROUP COM Put 2,500 198 n/a n/a n/a
2021-11-15 2021-09-30 13F COSTAR GROUP COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2021-08-16 2021-06-30 13F COSTAR GROUP COM Put 9,400 9,300.00 779 850.00 n/a n/a n/a
2021-05-17 2021-03-31 13F COSTAR GROUP COM Put 100 -98.94 82 -89.47 n/a n/a n/a
2021-02-16 2020-12-31 13F COSTAR GROUP COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2020-11-16 2020-09-30 13F COSTAR GROUP COM Put 400 -75.00 339 -70.18 n/a n/a n/a
2020-08-14 2020-06-30 13F COSTAR GROUP COM Put 1,600 100.00 1,137 141.91 n/a n/a n/a
2020-05-15 2020-03-31 13F COSTAR GROUP COM Put 800 -50.00 470 -58.66 n/a n/a n/a
2020-02-14 2019-12-31 13F COSTAR GROUP COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2019-11-14 2019-09-30 13F COSTAR GROUP COM Put 200 119 n/a n/a n/a
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.