Southwest Airlines Co.
MX ˙ BMV ˙ US8447411088
SecurityMX:LUV / Southwest Airlines Co.
InstitutionRhumbline Advisers
Latest Disclosed Ownership1,274,165 shares
Latest Disclosed Value $ 47,870,252
Rhumbline Advisers reports 2.50% decrease in ownership of LUV / Southwest Airlines Co.

On May 12, 2026 - Rhumbline Advisers filed a 13F-HR form disclosing ownership of 1,274,165 shares of Southwest Airlines Co. (MX:LUV) valued at $47,870,252 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 1,306,872 shares of Southwest Airlines Co.. This represents a change in shares of -2.50% during the quarter.

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 S.W. AIRL CO COM COM 844741108 1,274,165 -32,707 -2.50 47,870 -11.37 0.0410
2026-02-13 2025-12-31 13F S.W. AIRL CO COM COM 844741108 1,306,872 -56,203 -4.12 54,013 24.18 0.0437
2025-11-06 2025-09-30 13F S.W. AIRL CO COM COM 844741108 1,363,075 -43,577 -3.10 43,496 -4.68 0.0349
2025-08-12 2025-06-30 13F S.W. AIRL CO COM COM 844741108 1,406,652 325,030 30.05 45,632 25.64 0.0391
2025-05-29 2025-03-31 13F/A-1 S.W. AIRL CO COM COM 844741108 1,081,622 36,822 3.52 36,321 3.40 0.0340
2025-04-08 2025-03-31 13F S.W. AIRL CO COM COM 844741108 1,081,622 36,822 36,321 0.0340
2025-05-29 2024-12-31 13F/A-1 S.W. AIRL CO COM COM 844741108 1,044,800 -11,178 -1.06 35,126 12.27 0.0314
2025-01-30 2024-12-31 13F S.W. AIRL CO COM COM 844741108 1,044,800 -11,178 35,126 0.0314
2024-11-12 2024-09-30 13F S.W. AIRL CO COM COM 844741108 1,055,978 -51,529 -4.65 31,289 -1.25 0.0282
2024-08-01 2024-06-30 13F S.W. AIRL CO COM COM 844741108 1,107,507 14,017 1.28 31,686 -0.73 0.0298
2024-05-09 2024-03-31 13F S.W. AIRL CO COM COM 844741108 1,093,490 -66,762 -5.75 31,919 -4.74 0.0307
2024-02-08 2023-12-31 13F S.W. AIRL CO COM COM 844741108 1,160,252 13,517 1.18 33,508 7.94 0.0351
2023-11-09 2023-09-30 13F S.W. AIRL CO COM COM 844741108 1,146,735 31,595 2.83 31,042 -23.12 0.0360
2023-08-08 2023-06-30 13F S.W. AIRL CO COM COM 844741108 1,115,140 -20,095 -1.77 40,379 112,063.89 0.0452
2023-05-11 2023-03-31 13F S.W. AIRL CO COM COM 844741108 1,135,235 1,903 0.17 37 -99.91 0.0456
2023-02-14 2022-12-31 13F S.W. AIRL CO COM COM 844741108 1,133,332 35,178 3.20 38,159 12.67 0.0513
2022-11-10 2022-09-30 13F S.W. AIRL CO COM COM 844741108 1,098,154 38,387 3.62 33,867 -11.53 0.0504
2022-08-11 2022-06-30 13F S.W. AIRL CO COM COM 844741108 1,059,767 99,471 10.36 38,279 -12.97 0.0559
2022-05-12 2022-03-31 13F S.W. AIRL CO COM COM 844741108 960,296 39,388 4.28 43,982 11.48 0.0566
2022-02-10 2021-12-31 13F S.W. AIRL CO COM COM 844741108 920,908 -4,551 -0.49 39,452 -17.11 0.0484
2021-11-12 2021-09-30 13F S.W. AIRL CO COM COM 844741108 925,459 -31,362 -3.28 47,596 -6.30 0.0644
2021-08-05 2021-06-30 13F S.W. AIRL CO COM COM 844741108 956,821 -36,703 -3.69 50,798 -16.26 0.0667
2021-05-06 2021-03-31 13F S.W. AIRL CO COM COM 844741108 993,524 -87,494 -8.09 60,665 20.40 0.0824
2021-02-10 2020-12-31 13F S.W. AIRL CO COM COM 844741108 1,081,018 5,706 0.53 50,386 24.95 0.0695
2020-11-12 2020-09-30 13F S.W. AIRL CO COM COM 844741108 1,075,312 -95,047 -8.12 40,324 0.80 0.0632
2020-08-13 2020-06-30 13F S.W. AIRL CO COM COM 844741108 1,170,359 102,134 9.56 40,003 5.16 0.0668
2020-05-06 2020-03-31 13F S.W. AIRL CO COM COM 844741108 1,068,225 3,311 0.31 38,039 -33.83 0.0797
2020-02-05 2019-12-31 13F S.W. AIRL CO COM COM 844741108 1,064,914 -1,665 -0.16 57,484 -0.21 0.0961
2019-10-23 2019-09-30 13F S.W. AIRL CO COM COM 844741108 1,066,579 40,863 3.98 57,606 10.60 0.1053
2019-08-14 2019-06-30 13F S.W. AIRL CO COM COM 844741108 1,025,716 30,934 3.11 52,086 0.87 0.0978
2019-05-01 2019-03-31 13F S.W. AIRL CO COM COM 844741108 994,782 18,162 1.86 51,639 13.76 0.1000
2019-01-31 2018-12-31 13F S.W. AIRL CO COM COM 844741108 976,620 -12,297 -1.24 45,393 -26.50 0.0988
2018-11-07 2018-09-30 13F S.W. AIRL CO COM COM 844741108 988,917 -10,630 -1.06 61,758 21.43 0.1193
2018-08-06 2018-06-30 13F S.W. AIRL CO COM COM 844741108 999,547 -9,410 -0.93 50,857 -12.00 0.1026
2018-05-02 2018-03-31 13F S.W. AIRL CO COM COM 844741108 1,008,957 -14,432 -1.41 57,793 -13.72 0.1207
2018-02-09 2017-12-31 13F S.W. AIRL CO COM COM 844741108 1,023,389 5,181 0.51 66,981 17.51 0.1360
2017-11-06 2017-09-30 13F S.W. AIRL CO COM COM 844741108 1,018,208 -38,161 -3.61 56,999 -13.17 0.1239
2017-08-02 2017-06-30 13F S.W. AIRL CO COM COM 844741108 1,056,369 -45,980 -4.17 65,643 10.77 0.1498
2017-05-02 2017-03-31 13F S.W. AIRL CO COM COM 844741108 1,102,349 73,910 7.19 59,262 15.62 0.1384
2017-01-27 2016-12-31 13F S.W. AIRL CO COM COM 844741108 1,028,439 28,858 2.89 51,257 31.85 0.1299
2016-11-08 2016-09-30 13F S.W. AIRL CO COM COM 844741108 999,581 29,726 3.06 38,874 2.22 0.1071
2016-08-11 2016-06-30 13F S.W. AIRL CO COM COM 844741108 969,855 -77,106 -7.36 38,028 -18.92 0.1127
2016-05-02 2016-03-31 13F SOUTHWEST AIRLINES CO COMMON S COM 844741108 1,046,961 2,252 0.22 46,904 4.27 0.1455
2016-02-03 2015-12-31 13F SOUTHWEST AIRLINES CO COMMON S COM 844741108 1,044,709 -15,160 -1.43 44,985 11.58 0.1448
2015-11-04 2015-09-30 13F SOUTHWEST AIRLINES CO COMMON S COM 844741108 1,059,869 3,933 0.37 40,317 15.39 0.1372
2015-08-04 2015-06-30 13F SOUTHWEST AIRLINES CO COMMON S COM 844741108 1,055,936 86,202 8.89 34,941 -18.66 0.1114
2015-05-12 2015-03-31 13F SOUTHWEST AIRLINES CO COMMON S COM 844741108 969,734 -6,744 -0.69 42,959 3.95 0.1239
2015-02-06 2014-12-31 13F SOUTHWEST AIRLINES CO COMMON S COM 844741108 976,478 -22,441 -2.25 41,325 22.51 0.1200
2014-11-12 2014-09-30 13F SOUTHWEST AIRLINES CO COMMON S COM 844741108 998,919 -13,178 -1.30 33,733 24.09 0.1013
2014-08-06 2014-06-30 13F SOUTHWEST AIRLINES CO COMMON S COM 844741108 1,012,097 58,117 6.09 27,185 20.70 0.0798
2014-05-06 2014-03-31 13F SOUTHWEST AIRLINES CO COMMON S COM 844741108 953,980 -38,627 -3.89 22,523 20.44 0.0668
2014-02-03 2013-12-31 13F SOUTHWEST AIRLINES CO COMMON S COM 844741108 992,607 -44,199 -4.26 18,701 23.88 0.0552
2013-11-05 2013-09-30 13F SOUTHWEST AIRLINES CO COMMON S COM 844741108 1,036,806 6,390 0.62 15,096 13.66 0.0468
2013-08-07 2013-06-30 13F SOUTHWEST AIRLINES CO COMMON S COM 844741108 1,030,416 1,030,416 13,282 0.0427
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.