NiSource 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 865 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

• The NIPSCO minority sale: NiSource sold a 19.9% equity interest in NIPSCO Holdings II LLC (sole owner of the operating utility NIPSCO) to a Blackstone Infrastructure Partners affiliate in December 2023 for $2.16 billion cash. NiSource retains the other 80.1% and consolidates NIPSCO Holdings II under the voting interest model (not as a VIE). This is recorded as a holding at NiSource's own 80.1%, per this project's convention for a controlled-but-not-wholly-owned consolidated subsidiary. The instrument on both sides is an unlisted LLC equity/membership interest, not common stock; there is no current market value disclosed, so shares and value_usd are null rather than modelled from the 2023 transaction price.
• A second, smaller, structurally identical transaction (the 'GenCo Minority Interest Transaction') closed October 2025: NiSource issued a 19.9% equity interest in Generation Holdings II LLC (sole owner of GenCo, the generation-development subsidiary) to Blackstone affiliates BIP Orion Holdco L.P. and BIP Orion Holdco II L.P. for an initial $35.2 million, with up to $1.325 billion more available from Blackstone over 7 years. NiSource retains 80.1%, confirmed unchanged as of the Q2 2026 10-Q (period 30 Jun 2026). Generation Holdings II is consolidated as a VIE.
• NiSource's noncontrolling-interest balance sheet line (within total equity) sizes the Blackstone minority interests in NIPSCO Holdings II and Generation Holdings II combined; it was deliberately NOT used to size NiSource's own 80.1% retained stake in either entity, per the explicit instruction for this research task.
• NIPSCO also consolidates four renewable-energy joint ventures as VIEs (Rosewater and Indiana Crossroads Wind; Indiana Crossroads Solar and Dunns Bridge I), each with third-party tax equity partners under HLBV accounting. No specific NiSource ownership percentage is disclosed for these in the FY2025 10-K or the FY2025 Exhibit 21 (a plain subsidiary name list with no ownership-percentage column, like Darden's and Labcorp's per this project's prior findings), so these are not sized as holdings here; see unknowns.
• Register: 8 rows (7 institutional index/active managers plus the directors-and-officers-as-a-group insider row), summing to 206,879,584 shares against 479,560,100 shares outstanding, computed exactly as the chart's self-gate formula specifies (no is_aggregate/rolls_up_into rows present, so every row counts at full value): 206,879,584 / 479,560,100 = 43.14%.
• T. Rowe Price and Cohen & Steers both file 13F value columns in THOUSANDS of dollars for this quarter; confirmed via the implied-price-per-share check against the cross-filer cluster (~$47.5-47.6/share for period 30 Jun 2026). value_usd left null on those rows rather than guessed at scale.
• Capital Group's three main registrants (Capital World Investors 0001422849, Capital International Investors 0001562230, Capital Research Global Investors 0001422848) were each checked by full-CUSIP search of their Q2 2026 13F-HR information tables (637, 446 and 426 rows respectively) and hold zero NiSource shares; not included as a row.
• NiSource also has outstanding preferred stock (Series A, B and C, aggregate liquidation preference $400M/$500M/$863M respectively per the FY2025 10-K) and, via the NIPSCO/GenCo minority transactions, LLC equity units held by Blackstone in non-listed subsidiaries. No preferred or non-common instrument is counted into shares_outstanding or into any register row's shares; every register row above was matched against CUSIP 65473P105, the common stock CUSIP.
• DEF 14A 5% owner figures (Vanguard 53,932,502/11.3%, T. Rowe Price IM 50,331,635/10.5%, BlackRock 47,256,914/9.9%, State Street 23,762,068/5.0%, all as of 16 Mar 2026 per stale Schedule 13G data) are superseded in this file by fresh Q2 2026 13F-HR figures per this project's convention; both figures are recorded here for reconciliation rather than one overwriting the other.