Teradyne, 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 1,208 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

• Treasury and marketable securities are explicitly excluded from holdings, per the brief. Teradyne's Q2 2026 10-Q balance sheet reports 'Marketable securities' of $162.274 million at 28 Jun 2026 (up from $126.256 million at 31 Dec 2025), plus cash and cash equivalents, held as corporate treasury (a test-equipment maker's investment portfolio funding operations and buybacks). This is treasury management, not a strategic equity stake in another operating company, and is not reflected anywhere in holdings.
• Convertible notes are excluded from the share count, per the brief. Teradyne's Q2 2026 10-Q was searched for 'convertible notes' and 'convertible senior' and returned zero hits: Teradyne carries no outstanding convertible debt as of 28 Jun 2026 (its prior convertible senior notes matured and were settled in earlier years), so there was nothing to wrongly add to shares_outstanding. company.shares_outstanding (156,340,750) is taken as-is from the 10-Q cover page, 'shares outstanding of the registrant's only class of Common Stock as of July 27, 2026'. No stock split was found in the 10-Q or 10-K searched ('stock split' returned zero hits), so no restatement of any register row was needed.
• Holdings side: two positions found, on opposite sides of the wholly owned/genuine minority line, both from Teradyne's own 10-Q and 10-K. (1) Technoprobe S.p.A.: a genuine 10% equity-method minority stake in a separate, publicly traded Italian company (Euronext Milan: TPRO), acquired May 2024, board seat, accounted for as an equity method investment because Teradyne has significant influence but not control. This is squarely a holding under the brief. (2) MultiLane Test Products Holding LLP (MLTP): a joint venture formed April 2026 in which Teradyne holds a controlling 75% interest and consolidates the entity, while HTP Holding SAL (MultiLane) holds a genuine 25% noncontrolling interest. Per the brief's Nucor/Moody's ICRA precedent, a subsidiary the company consolidates while a third party holds a real minority is a holding, not an excluded wholly owned subsidiary, so MLTP is included too, at Teradyne's 75% interest. By contrast, Teradyne's other 2024-2025 acquisitions (Quantifi Photonics, AET, and its earlier Universal Robots/MiR/Energid/Lemsys/AutoGuide robotics purchases referenced in the 10-K) are wholly owned operating subsidiaries and correctly excluded: the Q2 2026 10-Q's balance sheet shows 'Equity attributable to noncontrolling interests' of $36.151 million at 28 Jun 2026 versus $0 at 31 Dec 2025, confirming MLTP (formed Apr 2026) is the only entity in the group with a real third-party minority; everything else Teradyne owns is 100% owned.
• Search terms run against the Q2 2026 10-Q and FY2025 10-K per the brief: 'equity method' (found Technoprobe), 'non-marketable' (0 hits), 'strategic investment' (hits, but all refer to R&D/opex spending language, not an investment position), 'privately held' (found only the wholly owned Quantifi Photonics acquisition), 'joint venture' (found MLTP), 'unconsolidated' (0 hits), 'noncontrolling interest' (found MLTP's NCI), 'minority interest' (0 hits), 'cost method' (0 hits), 'equity investments' (0 hits). No combined, unnamed-investee equity-method balance was found: Technoprobe is the sole named equity-method investment on Teradyne's balance sheet ($514.957 million carrying value at 28 Jun 2026), so the 'never assign a combined balance to one investee' issue does not arise here; the whole equity method investment line is Technoprobe alone.
• Register: 15 institutional/13F rows (13 nonzero plus Dodge & Cox and Berkshire Hathaway included as explicit zero rows to document that both were checked and neither holds TER, per the brief's warning that these two are commonly missed) plus 2 insider rows sourced from the 2026 proxy, 17 rows total. Vanguard's parent CIK 0000102909 filed Form 13F-NT for Q2 2026 (confirmed), so its position is the sum of five successor entities: Vanguard Capital Management LLC, Vanguard Portfolio Management LLC, Vanguard Global Advisers LLC, Vanguard Personalized Indexing Management LLC, and Vanguard Advisers Inc (the last holds 0 TER shares but was checked). T. Rowe Price and Capital Group are both roll-ups of separately registered entities within each family (no parent 13F-NT for either family), not proxy aggregates. Wellington Management Group LLP (CIK 0000902219, the parent) is the entity that actually carries TER; its five operating-subsidiary CIKs each filed 13F-NT and hold nothing individually, the reverse pattern from Vanguard where the PARENT files NT.
• Self-gate, computed with the chart's own formula: 17 register rows, summing to 69,856,464 shares (each institutional row and Gregory S. Smith at full value; the 15-person officer/director group counted at its residual of 292,900 minus Smith's 118,581 = 174,319 to avoid double counting his position), against 156,340,750 shares outstanding, or 44.68%. This is above the brief's typical 25-45% band but below the 55% threshold that would require a rework; no double counted holder or mixed instrument was found on review, and every register share count was cross-checked for a consistent implied price per share of roughly $483.8 to $483.9 (the 30 Jun 2026 TER closing price) across all filers, confirming a single consistent basis throughout. CORRECTION, made by the coordinator before this file was committed: this note originally asserted 71,771,107 shares and 45.91%, a figure that cannot be reproduced from this file's own register. The rows sum to 69,975,045 naively and 69,856,464 under the chart formula, so the asserted total was 1,796,062 shares too high and appears to have come from an earlier draft of the register. The chart itself was never wrong; only the note was. Recomputed independently and corrected to 44.68%, which remains above the typical 25 to 45 per cent band and below the 55 per cent rework threshold, so the conclusion the note drew is unchanged.
• The 2026 proxy's own 5%-holder table (based on stale Schedule 13G/A filings) names only Vanguard (13.4%, 20,972,755 shares) and BlackRock (9.2%, 14,337,126 shares) plus FMR LLC (5.1%, 7,910,777 shares) as 5%+ holders, all lower share counts for BlackRock and FMR than or different in mix from the fresher Q2 2026 13F-HR figures used in the register (BlackRock's 13F position of 19,437,021 shares is notably higher than its stale 13G figure of 14,337,126, consistent with BlackRock adding to its position since the 13G's underlying date; FMR's 13F position of 4,105,776 is lower than its stale 13G figure of 7,910,777, consistent with FMR trimming). The register uses the more current 13F-HR data as the primary sourced numbers rather than the proxy's stale 13G table.
• Teradyne has a single class of common stock, one vote per share, no dual-class or founder-control structure. CEO Gregory S. Smith's and the full 15-person officer/director group's beneficial ownership are each under 1% of shares outstanding per the proxy; there is no insider-control story here comparable to a founder-led company.