CarMax, Inc.
MX ˙ BMV ˙ US1431301027
SecurityMX:KMX / CarMax, Inc.
InstitutionTwin Tree Management, LP
Latest Disclosed Ownership9,271 shares
Latest Disclosed Value $ 385,488
Twin Tree Management, LP ownership in KMX / CarMax, Inc.

On May 14, 2026 - Twin Tree Management, LP filed a 13F-HR form disclosing ownership of 9,271 shares of CarMax, Inc. (MX:KMX) valued at $385,488 USD as of March 31, 2026. The entity filed a previous 13F-HR on November 13, 2025 disclosing 0 shares of CarMax, Inc..

Twin Tree Management, LP has a history of taking positions in derivatives of the underlying security (KMX) in the form of stock options. The firm currently holds call options representing 3,300 of underlying shares valued at $137,214 USD and put options representing 33,100 of underlying shares valued at $1,376,298 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:KMX / CarMax, 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)
2026-05-14 2026-03-31 13F CARMAX COM 143130102 9,271 9,271 385 0.0081
2025-11-13 2025-09-30 13F CARMAX COM 143130102 0 -129,454 -100.00 0 -100.00
2025-07-28 2025-06-30 13F CARMAX COM 143130102 129,454 129,454 8,701 0.0162
2025-05-15 2025-03-31 13F CARMAX ORDINARY SHARES 143130102 0 -28,335 -100.00 0 -100.00
2025-02-10 2024-12-31 13F CARMAX ORDINARY SHARES 143130102 28,335 28,335 2,317 0.0041
2024-05-09 2024-03-31 13F CARMAX COM 143130102 0 -89,151 -100.00 0 -100.00
2024-02-14 2023-12-31 13F CARMAX COM 143130102 89,151 81,542 1,071.65 6,841 1,171.56 0.0131
2023-11-14 2023-09-30 13F CARMAX COM 143130102 7,609 -167,088 -95.64 538 -96.32 0.0012
2023-08-11 2023-06-30 13F CARMAX COM 143130102 174,697 143,143 453.64 14,622 621.01 0.0224
2023-05-10 2023-03-31 13F CARMAX COM 143130102 31,554 31,554 2,028 0.0038
2022-08-11 2022-06-30 13F CARMAX COM 143130102 0 -102,412 -100.00 0 -100.00
2022-05-11 2022-03-31 13F CARMAX COM 143130102 102,412 49,369 93.07 9,881 43.04 0.0158
2022-02-10 2021-12-31 13F CARMAX COM 143130102 53,043 53,043 6,908 0.0144
2021-02-12 2020-12-31 13F CARMAX COM 143130102 0 -83 -100.00 0 -100.00
2020-11-13 2020-09-30 13F CARMAX COM 143130102 83 83 8 0.0000
2019-11-12 2019-09-30 13F CARMAX ORDINARY SHARES 143130102 0 -60,883 -100.00 0 -100.00
2019-08-12 2019-06-30 13F CARMAX ORDINARY SHARES 143130102 60,883 35,375 138.68 5,286 196.97 0.0258
2019-05-10 2019-03-31 13F CARMAX ORDINARY SHARES 143130102 25,508 25,508 1,780 0.0092
2018-11-09 2018-09-30 13F CARMAX ORDINARY SHARES 143130102 0 -28,794 -100.00 0 -100.00
2018-08-07 2018-06-30 13F CARMAX ORDINARY SHARES 143130102 28,794 28,794 2,098 0.0129
2018-05-09 2018-03-31 13F CARMAX COM 143130102 0 -127 -100.00 0 -100.00
2018-02-09 2017-12-31 13F CARMAX COM 143130102 127 127 8 0.0001
2017-11-13 2017-09-30 13F CARMAX COM 143130102 0 -100,416 -100.00 0 -100.00
2017-08-10 2017-06-30 13F CARMAX COM 143130102 100,416 93,844 1,427.94 6,332 1,527.76 0.0495
2017-05-11 2017-03-31 13F CARMAX COM 143130102 6,572 -22,555 -77.44 389 -79.25 0.0035
2017-02-13 2016-12-31 13F CARMAX COM 143130102 29,127 29,127 1,875 0.0183
2016-11-15 2016-09-30 13F CARMAX COM 143130102 0 -3,935 -100.00 0 -100.00
2016-08-15 2016-06-30 13F CARMAX COM 143130102 3,935 -235 -5.64 193 -9.39 0.0030
2016-09-14 2016-03-31 13F/A-1 CARMAX COM 143130102 4,170 -2,228 -34.82 213 -38.26 0.0041
2016-05-16 2016-03-31 13F CARMAX COM 143130102 4,170 213
2016-09-14 2015-12-31 13F/A-1 CARMAX COM 143130102 6,398 -38,001 -85.59 345 -86.90 0.0068
2016-02-16 2015-12-31 13F CARMAX COM 143130102 6,398 345
2016-09-14 2015-09-30 13F/A-1 CARMAX COM 143130102 44,399 25,552 135.58 2,634 111.06 0.0675
2015-11-16 2015-09-30 13F CARMAX COM 143130102 44,399 2,634
2016-09-14 2015-06-30 13F/A-1 CARMAX COM 143130102 18,847 18,847 0.00 1,248 0.0303
2015-08-14 2015-06-30 13F CARMAX COM 143130102 18,847 1,248
2016-09-14 2014-12-31 13F/A-1 CARMAX COM 143130102 0 -36,152 -100.00 0 -100.00
2016-09-14 2014-09-30 13F/A-1 CARMAX COM 143130102 36,152 36,152 0.00 1,679 0.0446
2014-11-14 2014-09-30 13F CARMAX COM 143130102 36,152 1,679
2016-09-14 2014-06-30 13F/A-1 CARMAX COM 143130102 0 -3,314 -100.00 0 -100.00
2016-09-14 2014-03-31 13F/A-1 CARMAX COM 143130102 3,314 1,013 44.02 155 43.52 0.0031
2016-09-14 2013-12-31 13F/A-1 CARMAX COM 143130102 2,301 2,301 108 0.0026
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
(%)
2026-05-14 2026-03-31 13F CARMAX COM Call 3,300 -98.14 137 -98.00 n/a n/a n/a
2026-02-11 2025-12-31 13F CARMAX COM Call 177,300 103.09 6,851 74.88 n/a n/a n/a
2025-11-13 2025-09-30 13F CARMAX COM Call 87,300 -84.38 3,917 -89.57 n/a n/a n/a
2025-07-28 2025-06-30 13F CARMAX COM Call 558,900 -6.00 37,564 -18.92 n/a n/a n/a
2025-05-15 2025-03-31 13F CARMAX COM Call 594,600 83.29 46,331 74.69 n/a n/a n/a
2025-02-10 2024-12-31 13F CARMAX ORDINARY SHARES Call 324,400 -37.50 26,523 -33.96 n/a n/a n/a
2024-11-13 2024-09-30 13F CARMAX COM Call 519,000 57.03 40,160 65.69 n/a n/a n/a
2024-08-13 2024-06-30 13F CARMAX COM Call 330,500 -15.30 24,239 -28.69 n/a n/a n/a
2024-05-09 2024-03-31 13F CARMAX COM Call 390,200 63.13 33,990 85.17 n/a n/a n/a
2024-02-14 2023-12-31 13F CARMAX CALL Call 239,200 1,186.02 18,356 1,295.89 n/a n/a n/a
2023-11-14 2023-09-30 13F CARMAX CALL Call 18,600 1,316 n/a n/a n/a
2022-08-11 2022-06-30 13F CARMAX COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2022-05-11 2022-03-31 13F CARMAX COM Call 67,100 -42.16 6,474 -57.15 n/a n/a n/a
2022-02-10 2021-12-31 13F CARMAX COM Call 116,000 15,107 n/a n/a n/a
2020-11-13 2020-09-30 13F CARMAX COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2020-08-12 2020-06-30 13F CARMAX COM Call 119,100 -12.30 10,665 45.90 n/a n/a n/a
2020-05-13 2020-03-31 13F CARMAX COM Call 135,800 7,310 n/a n/a n/a
2019-08-12 2019-06-30 13F CARMAX ORDINARY SHARES Call 0 -100.00 0 -100.00 n/a n/a n/a
2019-05-10 2019-03-31 13F CARMAX ORDINARY SHARES Call 37,000 2,583 n/a n/a n/a
2018-05-09 2018-03-31 13F CARMAX COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2018-02-09 2017-12-31 13F CARMAX COM Call 49,300 -72.02 3,162 -76.33 n/a n/a n/a
2017-11-13 2017-09-30 13F CARMAX COM Call 176,200 13,358 n/a n/a n/a
2017-08-10 2017-06-30 13F CARMAX COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2017-05-11 2017-03-31 13F CARMAX COM Call 50,300 -68.24 2,979 -70.79 n/a n/a n/a
2017-02-13 2016-12-31 13F CARMAX COM Call 158,400 10,199 n/a n/a n/a
2016-09-14 2016-03-31 13F/A CARMAX COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2016-09-14 2015-12-31 13F/A CARMAX COM Call 900 -90.00 49 -90.82 n/a n/a n/a
2016-02-16 2015-12-31 13F CARMAX COM Call 9 0 n/a n/a n/a
2016-09-14 2015-09-30 13F/A CARMAX COM Call 9,000 -22.41 534 -30.47 n/a n/a n/a
2015-11-16 2015-09-30 13F CARMAX COM Call 90 5 n/a n/a n/a
2016-09-14 2015-06-30 13F/A CARMAX COM Call 11,600 -30.12 768 -32.98 n/a n/a n/a
2015-08-14 2015-06-30 13F CARMAX COM Call 116 8 n/a n/a n/a
2016-09-14 2015-03-31 13F/A CARMAX COM Call 16,600 -64.15 1,146 -62.83 n/a n/a n/a
2016-09-14 2014-12-31 13F/A CARMAX COM Call 46,300 13.20 3,083 62.26 n/a n/a n/a
2016-09-14 2014-09-30 13F/A CARMAX COM Call 40,900 13,533.33 1,900 11,775.00 n/a n/a n/a
2014-11-14 2014-09-30 13F CARMAX COM Call 409 19 n/a n/a n/a
2016-09-14 2014-06-30 13F/A CARMAX COM Call 300 -98.72 16 -98.54 n/a n/a n/a
2016-09-14 2014-03-31 13F/A CARMAX COM Call 23,400 1,095 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
(%)
2026-05-14 2026-03-31 13F CARMAX COM Put 33,100 -22.48 1,376 -16.56 n/a n/a n/a
2026-02-11 2025-12-31 13F CARMAX COM Put 42,700 -65.59 1,650 -70.38 n/a n/a n/a
2025-11-13 2025-09-30 13F CARMAX COM Put 124,100 -33.10 5,568 -55.34 n/a n/a n/a
2025-07-28 2025-06-30 13F CARMAX COM Put 185,500 -18.46 12,467 -29.67 n/a n/a n/a
2025-05-15 2025-03-31 13F CARMAX COM Put 227,500 73.53 17,727 65.39 n/a n/a n/a
2025-02-10 2024-12-31 13F CARMAX ORDINARY SHARES Put 131,100 -6.09 10,719 -0.78 n/a n/a n/a
2024-11-13 2024-09-30 13F CARMAX COM Put 139,600 -4.71 10,802 0.54 n/a n/a n/a
2024-08-13 2024-06-30 13F CARMAX COM Put 146,500 201.44 10,744 153.82 n/a n/a n/a
2024-05-09 2024-03-31 13F CARMAX COM Put 48,600 -58.14 4,234 -52.49 n/a n/a n/a
2024-02-14 2023-12-31 13F CARMAX PUT Put 116,100 141.37 8,910 161.88 n/a n/a n/a
2023-11-14 2023-09-30 13F CARMAX PUT Put 48,100 3,402 n/a n/a n/a
2023-02-13 2022-12-31 13F CARMAX PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2022-11-10 2022-09-30 13F CARMAX PUT Put 85,300 0.00 5,632 -27.03 n/a n/a n/a
2022-08-11 2022-06-30 13F CARMAX PUT Put 85,300 -59.36 7,718 -61.89 n/a n/a n/a
2022-05-11 2022-03-31 13F CARMAX COM Put 209,900 -27.57 20,251 -46.34 n/a n/a n/a
2022-02-10 2021-12-31 13F CARMAX COM Put 289,800 37,741 n/a n/a n/a
2021-05-17 2021-03-31 13F CARMAX COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2021-02-12 2020-12-31 13F CARMAX COM Put 62,200 -36.98 5,875 -35.24 n/a n/a n/a
2020-11-13 2020-09-30 13F CARMAX COM Put 98,700 -11.80 9,072 -9.47 n/a n/a n/a
2020-08-12 2020-06-30 13F CARMAX COM Put 111,900 256.37 10,021 492.96 n/a n/a n/a
2020-05-13 2020-03-31 13F CARMAX COM Put 31,400 1,690 n/a n/a n/a
2018-02-09 2017-12-31 13F CARMAX COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2017-11-13 2017-09-30 13F CARMAX COM Put 52,300 -11.21 3,965 6.76 n/a n/a n/a
2017-08-10 2017-06-30 13F CARMAX COM Put 58,900 3,714 n/a n/a n/a
2017-05-11 2017-03-31 13F CARMAX COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2017-02-13 2016-12-31 13F CARMAX COM Put 203,200 1,109.52 13,084 1,360.27 n/a n/a n/a
2016-11-15 2016-09-30 13F CARMAX COM Put 16,800 -2.89 896 5.66 n/a n/a n/a
2016-08-15 2016-06-30 13F CARMAX COM Put 17,300 848 n/a n/a n/a
2016-09-14 2016-03-31 13F/A CARMAX COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2016-09-14 2015-12-31 13F/A CARMAX COM Put 11,500 -82.44 621 -84.02 n/a n/a n/a
2016-02-16 2015-12-31 13F CARMAX COM Put 115 6 n/a n/a n/a
2016-09-14 2015-09-30 13F/A CARMAX COM Put 65,500 -53.38 3,885 -58.24 n/a n/a n/a
2015-11-16 2015-09-30 13F CARMAX COM Put 655 39 n/a n/a n/a
2016-09-14 2015-06-30 13F/A CARMAX COM Put 140,500 34.71 9,303 29.24 n/a n/a n/a
2015-08-14 2015-06-30 13F CARMAX COM Put 1,405 93 n/a n/a n/a
2016-09-14 2015-03-31 13F/A CARMAX COM Put 104,300 56.61 7,198 62.34 n/a n/a n/a
2016-09-14 2014-12-31 13F/A CARMAX COM Put 66,600 -36.02 4,434 -8.29 n/a n/a n/a
2016-09-14 2014-09-30 13F/A CARMAX COM Put 104,100 4,835 n/a n/a n/a
2014-11-14 2014-09-30 13F CARMAX COM Put 1,041 48 n/a n/a n/a
2016-09-14 2014-06-30 13F/A CARMAX COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2016-09-14 2014-03-31 13F/A CARMAX COM Put 24,300 305.00 1,137 303.19 n/a n/a n/a
2016-09-14 2013-12-31 13F/A CARMAX COM Put 6,000 282 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.