Southwest Airlines Co.

The full register, from 13F filings

The Register tab above is hand research: a dozen holders, each traced to the filing it came from. This asks the same question of the whole market for the quarter ended 31-mar-2026, where 854 managers reported a position. Broad where the research is deep, and shallow in the ways a 13F always is.

Built from 13F filings, which report US listed, long, US custodied positions only. A register from this source is a floor rather than a level: a holder's true position can be far larger, as BlackRock's ASML stake shows at 1.28m shares in a 13F against 26.3m in its 13G/A. Holdings held through derivatives, outside US custody, or below a manager's reporting obligation do not appear. Where a holder is marked as a family, its total sums several separate filing entities and describes something no single filing describes; the constituent entities and their share counts are listed so the total can be checked. That roll-up can legitimately exceed the family's own Schedule 13G, because a 13G is filed by one legal entity: Vanguard reports Alphabet through ten advisory entities, and The Vanguard Group Inc itself reported zero after its January 2026 disaggregation.

What a reader needs to know to read these numbers

• HOLDINGS SIDE IS EMPTY. Searched Southwest's FY2025 Form 10-K (filed 5 Feb 2026, covering fiscal year 2025) and its Q2 2026 Form 10-Q (filed 23 Jul 2026, period ended 30 Jun 2026) for the terms 'equity method', 'unconsolidated', 'minority interest', 'equity securities', 'strategic investment', 'non-marketable', 'joint venture', 'investments in', 'cost method', 'available-for-sale', 'fair value option', 'equity interest', and 'affiliate'. Zero hits for 'equity method', 'unconsolidated', 'minority interest', 'non-marketable', 'strategic investment', 'equity interest', 'affiliate', and 'fair value option' in either filing. The only 'equity securities' hits refer to mutual-fund holdings inside Southwest's own deferred-compensation and excess-benefit plans (an employee-benefit asset, not a stake in another operating company). The only 'joint venture' hit in the 10-K refers to COMPETITOR airlines' alliance structures, not anything Southwest itself holds. Also checked Exhibit 21 (subsidiaries list) of the FY2025 10-K: a plain name-and-jurisdiction list with NO ownership-percentage column (AirTran Airways, Inc.; AirTran Holdings, LLC; Southwest Jet Fuel Co.; Triple Crown Assurance Co. (a wholly owned captive insurer); Southwest Airlines India Private Limited), all of which read as wholly owned operating or captive subsidiaries rather than minority equity stakes. This is the same 'bare name list, genuine negative' pattern the brief describes for Labcorp and Darden.
• Southwest has interline/connectivity PARTNERSHIP agreements (commercial, not equity) with Icelandair, China Airlines, EVA Air, Philippine Airlines, Condor, Turkish Airlines, and Hahnair, per both the 10-K's Item 1 business description and its risk factors. These are explicitly described only as interline and codeshare-capability arrangements for transoceanic connectivity, with no ownership percentage, investment, or equity stake disclosed anywhere in connection with them. Excluded from holdings per the brief's rule that a codeshare/interline/alliance agreement is a commercial arrangement, not an equity stake, the same distinction applied to Williams-Sonoma's franchise agreements and Expeditors' agency relationships earlier in this project.
• Southwest has bought back a large fraction of its shares recently: common shares outstanding fell from 599,737,219 as of the Elliott 13D/A signing (30 Oct 2024) to 492,327,968 as of the 2026 proxy's record date (28 Feb 2026) to 489,208,201 as of the Q2 2026 10-Q cover page (22 Jul 2026), an ~18.4% reduction over roughly 21 months. shares_outstanding above uses the freshest of these (489,208,201, 22 Jul 2026), which is also the figure used as the denominator for every Q2 2026 13F-based register row (13F 'as of' date 30 Jun 2026, close to the 22 Jul 2026 cover-page count). Per the brief's own warning, this buyback mechanically inflates every static institutional ownership percentage versus older snapshots; every register row here nonetheless uses the fresh, matching, non-stale denominator, not a stale one.
• Capital Group family checked across all three required CIKs for Q2 2026: Capital World Investors (CIK 0001422849), Capital International Investors (CIK 0001562230), and Capital Research Global Investors (CIK 0001422848) each hold ZERO Southwest shares (confirmed by the absence of any 'SOUTHWEST AIRL' issuer-name fragment in each entity's full Q2 2026 13F-HR info table). Per the project's rule, a holder checked and found at zero is recorded as a note, not a null row.
• T. Rowe Price Investment Management, Inc. (CIK 0001897612), the second required T. Rowe registrant, was checked and confirmed to hold ZERO Southwest shares in its Q2 2026 13F-HR; only T. Rowe Price Associates, Inc. (CIK 0000080255, in the register above) holds a position.
• State Street Global Advisors Trust Company (CIK 0001714343), named alongside State Street Corporation in Southwest's proxy 13G citation, files Form 13F-NT (a notice carrying no holdings) every quarter including Q2 2026, confirming its Southwest position is reported entirely within the parent State Street Corporation 13F-HR used in the register (this is the 'parent files 13F-HR with real holdings, subsidiary files 13F-NT' case from the brief; only one row is used, nothing is summed).
• No dedicated ESOP or employee stock ownership trust appears as a separately sized 5%-or-greater or otherwise distinctly disclosed holder in Southwest's proxy or 13F register. Southwest's 401(k) plans are described in the proxy only in the context of executive compensation/benefits, without a share count for any trustee holding Southwest stock on employees' behalf; not converted into an esop_trust row.
• The register was built from the top holders named in Southwest's own DEF 14A 5% table (Vanguard, PRIMECAP, Elliott, State Street, Franklin Resources, BlackRock) plus the largest remaining 13F filers seen in this project's own 31-Mar-2026 LUV register snapshot (T. Rowe Price, Geode, FMR/Fidelity), each refreshed against that holder's own Q2 2026 13F-HR per the brief's instruction to treat the project's own register snapshot as an entity-identification tool only, never as a source of figures. Smaller 13F filers visible in that snapshot (e.g. PAR Capital Management, Qube Research & Technologies, Arrowstreet Capital, Morgan Stanley, JPMorgan Chase, Bank of New York Mellon, Northern Trust, Goldman Sachs, Dimensional Fund Advisors, Ameriprise Financial, Invesco, Bank of America) were not individually refreshed within the time budget; if material, the true institutional total is somewhat higher than computed below.
• SELF-GATE, computed exactly as the register chart computes it (raw shares summed, aggregate/member logic applied; the one insider row here is neither is_aggregate nor rolls_up_into anything, so it counts at full value like every other row): 10 register rows summing to 279,381,472 shares against 489,208,201 shares outstanding, or 57.11%. This is above the 'roughly 25% to 45%, flag above 55%' guideline range in the brief. Checked for the four known failure modes and found none: (1) no non-common-stock units anywhere, every row is CUSIP 844741108 common stock shares from a 13F info table or the proxy's common-stock ownership table; (2) no pre/post-split mismatch, Southwest has not split its stock in the period covered; (3) no double-counted holder, Vanguard and State Street were each summed/selected using the documented parent-13F-NT-vs-successor-13F-HR rule, and Capital Group and T. Rowe Investment Management were checked and confirmed at zero rather than added; (4) no fractional shares. The elevated total is best explained by the ~18.4% share-count reduction from buybacks noted above (a fixed set of large institutional and strategic holders now represents a bigger slice of a smaller denominator) combined with unusually large concentrated active positions (PRIMECAP ~9.97%, Franklin Resources ~9.52%) and Elliott's still-large 4.97% stake, all independently verified against each filer's own fresh Q2 2026 13F-HR. Corroborated first-hand by the coordinator against this project's own 13F-derived register (data/registers/LUV.json, period 31 Mar 2026, separate pipeline): its top TEN holders sum to 58.35% of the same denominator against the 57.11% recorded here from ten rows, and total institutional ownership is 382,415,646 shares, 78.17%. Two independent derivations agreeing to within about one percentage point on the same row count is strong evidence the level is real. The Elliott decision is corroborated from the same source: that snapshot carries Elliott Investment Management at 30,346,000 shares at 31 Mar 2026 against the 24,308,000 recorded here from its own Q2 2026 13F common line, a continuing reduction in the same direction, and both figures sit far below the stale October 2024 Schedule 13D count of 59,666,500. Using the fresh 13F common-stock line rather than the 13D beneficial-ownership figure also keeps the instrument consistent, since the 13D separately disclosed cash-settled swaps over a further 8,104,000 shares that are not common stock. Separately checked and found NOT to be an issue here: the share count is stable across recent cover pages (491,317,990 at 3 Feb 2026, 488,773,713 at 22 Apr, 489,208,201 at 22 Jul), so unlike Crown Castle earlier in this project there is no material basis mismatch between the 30 Jun 2026 holder counts and the 22 Jul 2026 denominator.