Southwest Airlines Co.
MX ˙ BMV ˙ US8447411088
SecurityMX:LUV / Southwest Airlines Co.
InstitutionHeartland Advisors Inc
Latest Disclosed Ownership160,304 shares
Latest Disclosed Value $ 6,022,621
Heartland Advisors Inc reports 56.49% increase in ownership of LUV / Southwest Airlines Co.

On May 6, 2026 - Heartland Advisors Inc filed a 13F-HR form disclosing ownership of 160,304 shares of Southwest Airlines Co. (MX:LUV) valued at $6,022,621 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 11, 2026 disclosing 102,436 shares of Southwest Airlines Co.. This represents a change in shares of 56.49% 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)
2026-05-06 2026-03-31 13F SOUTHWEST AIRLS COM 844741108 160,304 57,868 56.49 6,023 42.26 0.3072
2026-02-11 2025-12-31 13F SOUTHWEST AIRLS COM 844741108 102,436 50,428 96.96 4,234 155.15 0.2280
2025-11-07 2025-09-30 13F SOUTHWEST AIRLS COM 844741108 52,008 -34,443 -39.84 1,660 -40.83 0.0877
2025-08-12 2025-06-30 13F SOUTHWEST AIRLS COM 844741108 86,451 -42,408 -32.91 2,804 -35.20 0.1564
2025-05-07 2025-03-31 13F SOUTHWEST AIRLS COM 844741108 128,859 128,859 4,327 0.2485
2014-05-09 2014-03-31 13F SOUTHWEST AIRLS COM 844741108 0 -589,265 -100.00 0 -100.00
2014-02-14 2013-12-31 13F SOUTHWEST AIRLS COM 844741108 589,265 -1,172,895 -66.56 11,102 -56.73 0.1929
2013-11-26 2013-09-30 13F/A-1 SOUTHWEST AIRLS COM 844741108 1,762,160 -24,891 -1.39 25,657 11.38 0.4674
2013-11-14 2013-09-30 13F SOUTHWEST AIRLS COM 844741108 1,762,160 25,657
2013-08-14 2013-06-30 13F SOUTHWEST AIRLS COM 844741108 1,787,051 1,787,051 23,035 0.4246
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.