Atmos Energy Corporation
US ˙ NYSE ˙ US0495601058

SecurityATO / Atmos Energy Corporation
InstitutionSei Investments Co
Latest Disclosed Ownership574,099 shares
Latest Disclosed Value $ 96,236,501
Sei Investments Co reports 9.99% decrease in ownership of ATO / Atmos Energy Corporation

On February 13, 2026 - Sei Investments Co filed a 13F-HR form disclosing ownership of 574,099 shares of Atmos Energy Corporation (US:ATO) valued at $96,236,215 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 13, 2025 disclosing 637,821 shares of Atmos Energy Corporation. This represents a change in shares of -9.99% during the quarter. The current value of the position is $96,620,862 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)
2026-02-13 2025-12-31 13F ATMOS ENERGY COM 049560105 574,099 -63,722 -9.99 96,237 -11.63 0.0950
2025-11-13 2025-09-30 13F ATMOS ENERGY COM 049560105 637,821 44,350 7.47 108,908 19.08 0.1171
2025-08-14 2025-06-30 13F ATMOS ENERGY COM 049560105 593,471 -3,820 -0.64 91,460 -0.94 0.1060
2025-05-14 2025-03-31 13F/A-1 ATMOS ENERGY COM 049560105 597,291 -3,163 -0.53 92,329 10.41 0.1188
2025-05-13 2025-03-31 13F ATMOS ENERGY COM 049560105 602,037 1,583 84,376 0.0918
2025-02-11 2024-12-31 13F ATMOS ENERGY COM 049560105 600,454 -83,866 -12.26 83,625 -11.90 0.1074
2024-11-12 2024-09-30 13F ATMOS ENERGY COM 049560105 684,320 68,862 11.19 94,921 32.21 0.1233
2024-08-13 2024-06-30 13F ATMOS ENERGY COM 049560105 615,458 41,376 7.21 71,793 5.21 0.1017
2024-05-07 2024-03-31 13F ATMOS ENERGY COM 049560105 574,082 67,489 13.32 68,241 16.23 0.1000
2024-02-14 2023-12-31 13F ATMOS ENERGY COM 049560105 506,593 2,849 0.57 58,714 10.03 0.0943
2023-11-14 2023-09-30 13F ATMOS ENERGY COM 049560105 503,744 -4,426 -0.87 53,362 -9.74 0.0959
2023-08-11 2023-06-30 13F ATMOS ENERGY COM 049560105 508,170 -30,442 -5.65 59,120 -2.31 0.1031
2023-05-12 2023-03-31 13F ATMOS ENERGY COM 049560105 538,612 -6,891 -1.26 60,518 -1.01 0.1124
2023-02-10 2022-12-31 13F ATMOS ENERGY COM 049560105 545,503 75,177 15.98 61,135 27.62 0.1359
2022-11-14 2022-09-30 13F ATMOS ENERGY COM 049560105 470,326 59,033 14.35 47,903 3.90 0.1069
2022-08-15 2022-06-30 13F ATMOS ENERGY COM 049560105 411,293 918 0.22 46,107 -5.98 0.0996
2022-05-13 2022-03-31 13F ATMOS ENERGY COM 049560105 410,375 245,409 148.76 49,037 183.71 0.0986
2022-02-14 2021-12-31 13F ATMOS ENERGY COM 049560105 164,966 12,609 8.28 17,284 28.62 0.0324
2021-11-12 2021-09-30 13F ATMOS ENERGY COM 049560105 152,357 4,230 2.86 13,438 -5.61 0.0282
2021-08-06 2021-06-30 13F ATMOS ENERGY COM 049560105 148,127 11,181 8.16 14,236 5.58 0.0316
2021-05-12 2021-03-31 13F ATMOS ENERGY COM 049560105 136,946 7,795 6.04 13,483 9.48 0.0340
2021-02-08 2020-12-31 13F ATMOS ENERGY COM 049560105 129,151 3,351 2.66 12,315 2.41 0.0318
2020-12-04 2020-09-30 13F/A-1 ATMOS ENERGY COM 049560105 125,800 28,081 28.74 12,025 23.57 0.0348
2020-11-06 2020-09-30 13F ATMOS ENERGY COM 049560105 126,449 28,730 12,087 29,102.8086
2020-08-17 2020-06-30 13F/A-1 ATMOS ENERGY COM 049560105 97,719 -25,143 -20.46 9,731 -20.19 0.0302
2020-08-11 2020-06-30 13F ATMOS ENERGY COM 049560105 111,876 -10,986 12,508 33,928.6158
2020-05-14 2020-03-31 13F ATMOS ENERGY COM 049560105 122,862 11,525 10.35 12,192 -2.10 0.0448
2020-02-06 2019-12-31 13F ATMOS ENERGY COM 049560105 111,337 -14,767 -11.71 12,454 -13.29 0.0371
2019-11-12 2019-09-30 13F ATMOS ENERGY COM 049560105 126,104 -3,175 -2.46 14,362 5.24 0.0367
2019-08-14 2019-06-30 13F ATMOS ENERGY COM 049560105 129,279 -16,503 -11.32 13,647 -9.05 0.0446
2019-05-15 2019-03-31 13F ATMOS ENERGY COM 049560105 145,782 789 0.54 15,005 10.20 0.0504
2019-02-13 2018-12-31 13F ATMOS ENERGY COM 049560105 144,993 -12,788 -8.10 13,616 -8.11 0.0485
2018-11-08 2018-09-30 13F ATMOS ENERGY COM 049560105 157,781 9,175 6.17 14,817 10.62 0.0537
2018-08-03 2018-06-30 13F ATMOS ENERGY COM 049560105 148,606 112,200 308.19 13,395 336.75 0.0455
2018-05-11 2018-03-31 13F ATMOS ENERGY COM 049560105 36,406 -196,990 -84.40 3,067 -84.54 0.0118
2018-02-08 2017-12-31 13F ATMOS ENERGY COM 049560105 233,396 -28,702 -10.95 19,836 -9.60 0.0689
2017-11-06 2017-09-30 13F ATMOS ENERGY COM 049560105 262,098 -3,255 -1.23 21,943 -0.31 0.0780
2017-07-31 2017-06-30 13F ATMOS ENERGY COM 049560105 265,353 -1,727 -0.65 22,011 4.33 0.0877
2017-05-05 2017-03-31 13F ATMOS ENERGY COM 049560105 267,080 52,501 24.47 21,097 32.69 0.0925
2017-02-02 2016-12-31 13F ATMOS ENERGY COM 049560105 214,579 33,242 18.33 15,900 17.74 0.0770
2016-11-04 2016-09-30 13F ATMOS ENERGY COM 049560105 181,337 1,256 0.70 13,504 -7.78 0.0686
2016-08-11 2016-06-30 13F ATMOS ENERGY COM 049560105 180,081 11,612 6.89 14,644 17.06 0.0878
2016-05-10 2016-03-31 13F/A-1 ATMOS ENERGY COM 049560105 168,469 44,945 36.39 12,510 60.65 0.0779
2016-02-03 2015-12-31 13F ATMOS ENERGY COM 049560105 123,524 96,958 364.97 7,787 404.01 0.0475
2015-11-02 2015-09-30 13F/A-1 ATMOS ENERGY COM 049560105 26,566 14,818 126.13 1,545 156.64 0.0142
2015-10-30 2015-09-30 13F ATMOS ENERGY COM 049560105 26,566 1,547
2015-08-07 2015-06-30 13F/A-1 ATMOS ENERGY COM 049560105 11,748 51 0.44 602 -6.81 0.0054
2015-08-04 2015-06-30 13F ATMOS ENERGY COM 049560105 11,748 51 602 0.0054
2015-05-14 2015-03-31 13F/A-1 ATMOS ENERGY COM 049560105 11,697 1,502 14.73 646 13.53 0.0056
2015-05-01 2015-03-31 13F ATMOS ENERGY COM 049560105 11,697 646
2015-02-10 2014-12-31 13F ATMOS ENERGY COM 049560105 10,195 10,195 569 0.0050
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.