Merck & Co., Inc.

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 3,731 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

• Merck itself files Form 13F-HR as an institutional investment manager (CIK 0000310158, co-filed with Merck Sharp & Dohme LLC, CIK 0000064978), which is the source for all 13 holdings rows above. This is unusual: most operating companies do not file 13F. The Q2 2026 filing (period ended 30 June 2026, filed 7 August 2026) lists 13 rows totaling 526,407,169 dollars, all of them minority equity stakes in small and mid-cap public biotech companies (Aktis Oncology, Alector, Eikon Therapeutics, Entrada Therapeutics, Evaxion Biotech, Kymera Therapeutics, Moderna, Neuphoria Therapeutics, Personalis, Sutro Biopharma, TuHURA Biosciences, Viridian Therapeutics, Xilio Therapeutics). These read as equity received or purchased alongside R&D collaboration and licensing deals rather than passive index-style investing, which is consistent with them being in scope as holdings under the brief.
• pct_of_target (Merck's ownership percentage of each investee) was not computed: that would require each investee's own shares-outstanding figure, which was not pulled within the time budget. Every holding above is null on pct_of_target and pct_denominator as a result; only Merck's own share count and dollar value from the 13F are recorded.
• value_price_per_share on each holding is arithmetic (reported dollar value divided by reported share count from the same 13F row), not an independently filed price; flagged per-row in method_note.
• Ticker symbols for the four most recently public names in the 13F (Aktis Oncology AKTS, Eikon Therapeutics EIKN, Neuphoria Therapeutics NEUP, TuHURA Biosciences HURA) were confirmed via web search on 17 August 2026 since these companies IPO'd in 2025 to 2026. The remaining nine tickers (ALEC, TRDA, EVAX, KYMR, MRNA, PSNL, STRO, VRDN, XLO) are long-established and were not individually re-verified by search; if any of these companies has since changed ticker, that would not be reflected here.
• 10-Q equity-investment text search: the Q2 FY2026 10-Q (period ended 30 June 2026, filed 7 August 2026) was not separately searched for 'equity method' or 'non-marketable equity securities' language because Merck's own 13F-HR already gives a directly filed, itemized list of its public minority equity stakes, which is the stronger source for that category. Any non-marketable (private-company) equity investments Merck may hold are not captured by the 13F (13F only covers Section 13(f) securities, i.e. exchange-traded/Nasdaq securities) and were not separately researched; see unknowns.
• Register uses different shares-outstanding denominators for different rows, matching what each source itself was closest to: the 30 June 2026 institutional 13F rows use 2,467,171,638 shares (10-Q cover page, as of 31 July 2026, the closest available count); Vanguard's row is dated 31 December 2025 but uses the same current denominator because a comparable year-end count was not pulled, so its percentage is a slight overstatement-risk approximation. The insider rows use 2,471,284,780 shares, the proxy's own stated count as of 28 February 2026.
• Vanguard disagreement, recorded rather than resolved. The Vanguard Group, Inc. (CIK 0000102909) last filed Form 13F-HR for the quarter ended 31 December 2025 (254,322,763 shares), then filed a Schedule 13G/A on 27 March 2026 reporting zero shares and zero percent effective 13 March 2026. A newly registered entity, Vanguard Capital Management LLC (CIK 0002100119, same Malvern, PA address as Vanguard), then filed a Schedule 13G on 30 April 2026 reporting 186,323,766 shares (7.53%) as of 31 March 2026. This looks like an internal Vanguard corporate reorganization of which entity holds reporting responsibility, not a real reduction in Vanguard's overall position, but it was not resolved within the time budget. The register above uses the older but more complete 13F-HR figure (254.3 million shares) rather than the lower, newly filed 13G figure, and this note documents the conflict.
• BlackRock's beneficial-ownership row in Merck's own proxy (201,836,434 shares, 8.17%) is sourced by the proxy itself to a Schedule 13G/A filed 26 January 2024 and is therefore stale next to BlackRock's own 30 June 2026 Form 13F-HR (226,999,837 shares) used in the register above.
• Merck has a single class of common stock; no dual-class or founder-control structure. No director or executive officer individually holds a material voting block; the CEO's 1,226,775 shares are roughly 0.05 percent of the company.
• Market capitalization ($334.43bn as of 13 August 2026) is from an aggregator (tipranks) and is rounded; it was not cross-derived from shares outstanding times a filed price within this task.