Pinnacle West Capital Corporation

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 691 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

• APS (Arizona Public Service Company) is a wholly owned subsidiary of Pinnacle West, confirmed directly from the Q2 2026 10-Q: 'Our reportable segment activities are conducted through our wholly-owned subsidiary, APS.' Per the brief, a wholly owned operating subsidiary is excluded from holdings. APS is itself an SEC registrant and files the 10-K/10-Q jointly with Pinnacle West, so the cover page carries both entities' share counts (Pinnacle West 121,197,234 shares; APS 71,264,947 shares, both as of 28 Jul 2026); company.shares_outstanding above uses the PINNACLE WEST figure only, per the brief's instruction.
• Palo Verde Nuclear Generating Station: APS is operator and co-owner of Palo Verde alongside several other utilities, holding an undivided percentage interest in the physical plant (proportionally consolidated), not equity in an operating company. This is not recorded as a holding, per the brief's explicit instruction not to record a plant participation percentage as a holding. It is not even reachable as a Pinnacle West position directly since it sits inside the wholly owned, excluded APS.
• Four Corners Power Plant: Pinnacle West's wholly owned subsidiary 4C Acquisition, LLC previously held a 7% undivided interest in Units 4 and 5 of Four Corners (a coal plant), the same 'physical asset participation' pattern as Palo Verde. That interest was SOLD to NTEC (Navajo Transitional Energy Company); Pinnacle West retained only a guarantee of certain of NTEC's obligations to the plant's other owners. Not recorded as a holding, both because it is a plant-participation interest and because it has been divested.
• El Dorado Investment Company (wholly owned) also holds a $25 million commitment to the Energy Impact Partners fund (about $21 million funded as of 30 Jun 2026), an organization focused on utility-industry innovation. Unlike SAI and Copper Sky, this investment does not appear in the 10-Q's equity-method ownership-percentage table, so no ownership percentage is disclosed for it; it looks like a passive LP-style fund commitment rather than a significant-influence equity stake, so it is not recorded as a holding, but is flagged here as checked.
• No Exhibit 21 (subsidiaries list) was filed with the FY2025 10-K (filed 25 Feb 2026, accession 0000764622-26-000011); its exhibit index runs EX-10.11 through EX-32.2 with no EX-21 present, so no percentage column could be checked there. All holdings-side figures instead came from the 10-Q's own equity-method investment table and surrounding prose.
• No SC 13D has ever been filed against Pinnacle West per EDGAR's filing history, and the only SC 13G/13G-A filings on record are dated 2022 through November 2024 (the routine annual index-manager notices); none has been refiled in 2025 or 2026 as of this research. The proxy's 5% table (as of 12 Mar 2026, Record Date) therefore still quotes those older 13G figures: Vanguard 14,282,050 (12.60%), Capital Research Global Investors and related entities 13,466,845 (11.30%), BlackRock 9,818,438 (8.20%), State Street 6,818,811 (6.02%), Barrow Hanley 6,684,100 (5.58%). This file uses the fresher Q2 2026 (30 Jun 2026) 13F-HR figures instead for all five, which are higher for Vanguard, BlackRock and State Street and lower for Capital Group and Barrow Hanley than the stale proxy numbers; both sets are kept here for reconciliation rather than one overwriting the other.
• Vanguard family: the parent, The Vanguard Group, Inc. (CIK 0000102909), filed Form 13F-NT (a notice carrying no holdings) for Q2 2026, so the position is reported entirely by seven successor entities, each fetched and summed individually: Vanguard Capital Management LLC (CIK 0002100119, 7,897,426 sh), Vanguard Portfolio Management LLC (0002100121, 5,986,758 sh), Vanguard Fiduciary Trust Co (0000933478, 680,544 sh), Vanguard Global Advisers LLC (0001811242, 249,344 sh), Vanguard Asset Management Ltd (0001680208, 98,750 sh), Vanguard Investments Australia Ltd (0001550100, 94,049 sh), and Vanguard Personalized Indexing Management LLC (0001767306, 16,989 sh), totaling 15,023,860 shares.
• Capital Group family: enumerated well beyond the register's own two listed CIKs by searching EDGAR's company database for every 'Capital Research', 'Capital World', 'Capital International', 'Capital Group' and 'Capital Guardian' registrant with a 13F filing history (13 candidates checked). Three parent-level entities filed 13F-NT for Q2 2026 (Capital Research & Management Co CIK 0000017283, Capital Group Companies, Inc. CIK 0000732812, Capital Group International, Inc. CIK 0000949308): no holdings reported at those levels. Among the remaining registrants, only three actually hold Pinnacle West stock: Capital Research Global Investors (CIK 0001422848, 16,494,147 sh), Capital International Sarl (CIK 0001065349, 4,211 sh), and Capital International Investors (CIK 0001562230, checked and confirmed at 0 shares this quarter). Capital World Investors (0001422849), Capital International, Inc./CA/ (0000895213), Capital International Ltd /CA/ (0001065350), and Capital Group Private Client Services, Inc. (0001857666) each filed 13F-HR for the quarter but held zero Pinnacle West shares. Family total: 16,498,358 shares.
• Both T. Rowe Price registrants were checked. T. Rowe Price Associates, Inc. (CIK 0000080255) holds 181,617 shares as of 30 Jun 2026; its information table reports value in THOUSANDS (raw value field 19,434 restated here as $19,434,000, confirmed against the implied per-share price of about $107 that every other row in this register also implies). T. Rowe Price Investment Management, Inc. (CIK 0001897612) was checked separately and holds 0 Pinnacle West shares this quarter, so it is not carried as its own row.
• Implied-price cross-check: value_usd divided by shares across every institutional row in this register (after restating T. Rowe Price out of thousands) lands within a few percent of $107 per share for all twelve rows, which is the consistency check the brief recommends. No row required a units correction beyond T. Rowe Price.
• Self-gate, computed from this file exactly as it sits on disk: 12 register rows. No row carries rolls_up_into, and the aggregate insiders/officers row has no members rolled into it (17 of its 20 members are individually named in the proxy at levels too small to be worth a separate row here, and none appears elsewhere in this register), so per the brief's formula every row counts at full value. Row total: 76,766,643 shares. Against shares_outstanding of 121,197,234, that is 63.34%, above the 25-45% band the brief describes as typical and above its 55% flag-for-investigation threshold. Investigated and not corrected: this register's 12 rows are a SUBSET of this project's own independent 13F-derived register for PNW (data/registers/PNW.json, a broader 31 Mar 2026 snapshot spanning 39 institutional holders), and this file's Q2 2026 top-12 total sits inside that larger all-filer total rather than exceeding it, which is the correct relationship for a subset. Combined with the implied-price consistency (every row in this register implies about $107 per share, with no outlier suggesting a units or double-counting error), the 63.34% reading is treated as a genuinely high but real institutional concentration for this small-cap ($12 billion) utility, not evidence of a mis-based or duplicated row.
• Market cap and shares outstanding cross-check: 121,197,234 shares at the roughly $107 per-share price implied by the Q2 2026 13F filings would be about $12.97 billion, close to (within normal timing/rounding of) the $12.05 billion market cap read from stockanalysis.com on 19 Aug 2026.