GetCoattail Research — The Filing Tape #78. BlackRock reported a record $15.49 trillion in assets under management on October 14, and the filings describe a six-name tracked cohort that cut its stake 31.90% in the second quarter, a full market that added 16.1 million shares, an insider record with zero open-market purchases, and a borrow 42.8% below its 2022 peak.
The Hype
BlackRock is the market's story of the day because it is the market's landlord. The firm reported third-quarter results before the open on October 14: adjusted earnings per share of $15.93, up 38% year over year and above the $14.32 consensus in FactSet-polled coverage; revenue of $7.75 billion, up 19%; net inflows of $205 billion in the quarter; and assets under management of $15.49 trillion, up 15% from a year earlier. Coverage recorded the shares up 3% in early New York trade, after a year in which the stock had languished — down 0.4% heading into Wednesday. Our own daily-close file ends earlier, on October 2, at $1,059.63 — down 1.0% year to date on that file, and 11.9% below the $1,202.59 closing high of October 15, 2025. BlackRock files other people's holdings for a living. The filings below answer a different question: who holds BlackRock.
The Tape
For BlackRock — the seventy-eighth Filing Tape audit — the tape shows a six-name tracked cohort whose share count fell 31.90% in the second quarter even as the full market added 16,124,184 shares, an insider record containing no open-market purchase at all against 87 sales, a congressional record of five sales and no purchase, a 5% register that is one passive holder's filing chain peaking at 6.87%, and a borrow 42.8% below its series maximum.
| Lens | As of | What the filings show | Direction vs prior period |
|---|---|---|---|
| Superinvestors (13F) | Jun 30, 2026 | 6 long holders; 868,402 shares; $835,020,627 | Rows 6 → 6; shares −31.90% as three holders cut |
| All institutions (13F) | Jun 30, 2026 | 2,308 filers; 119,228,122 shares | Filers +27; shares +15.64% |
| Insiders (Form 4) | Oct 2, 2026 | 0 purchases in the full parsed record; last 90 days: 3 sales | No purchase in any window of the record |
| Congress | Oct 3, 2026 | 0 purchases, 5 sales (House; Senate has no row) | No purchase date in the aggregate |
| 13D/G | Apr 27, 2026 | 2 parsed filings (all SC 13G-family); register maximum 6.87% (Vanguard) | Latest filing reports 6.87% under a successor reporting name |
| Short interest (FINRA) | Sep 15, 2026 | 2,040,079 shares; 1.32% of shares outstanding | Down 4.2% year over year; 42.8% below the series maximum |
Lens 1 — the superinvestors: six holders, and the top one is two-thirds. We track 83 large, mostly long-only managers whose 13F portfolios we collect directly from SEC EDGAR. As of June 30, 2026, 6 held BlackRock long, totalling 868,402 shares worth $835,020,627, with no option rows — every row on the current CUSIP. ValueAct Capital holds 581,700 shares worth $559,339,452 — 67.0% of the cohort's position — at a 9.93% weight, and it is the cohort's only increaser, up 6.5%. Behind it sit Markel Group (220,200 shares, unchanged), Oakmark Funds (44,575 shares, decreased 18.3%), Cantillon Capital Management (20,873 shares, decreased 95.4%), Dodge & Cox Funds (711 shares, unchanged) and Hillman Capital Management (343 shares, decreased 1.2%). Three of the six decreased, two were unchanged and one increased; no tracked manager entered or exited. On the pipeline's holdings files, the same six rows held 1,275,195 shares at March 31 and 868,402 at June 30 — down 406,793 shares (−31.90%). Cantillon's cut alone, from 453,282 shares to 20,873, is 432,409 shares — more than the cohort's whole net decline, partly offset by ValueAct's addition of 35,600 shares. The implied price, $961.56, sits exactly on the June 30 close. 13F figures are as of June 30, 2026; funds have up to 45 days to file, so this picture is complete — and always lagging.
Lens 2 — institutions: 27 more filers, 16.1 million more shares. At June 30, 2026, 2,308 institutions reported positions, up 27 from 2,281 at March 31 (+1.18%), 2,305 of them long. Reported shares rose 15.64%, from 103,103,938 to 119,228,122 shares. Reported value rose 15.82% to $115,016,420,396; the aggregate includes option rows, so we headline filer and share counts and label dollars "reported" (see methodology). BlackRock reports under two CUSIPs — the current one carries 119,101,952 of the shares, a legacy one a residual 126,170 — and the by-CUSIP rows sum to the by-ticker totals exactly. The full market added shares at a pace the tracked cohort did not join — the cohort's entire position is 868,402 shares, and it shrank by nearly a third.
Lens 3 — insiders: no purchase in the entire parsed record. The parsed Form 4 record holds 190 filings through October 2, 2026, and zero purchase transactions — in the last 90 days, in the last year, and across the full record — with zero officer purchases in every window. The 90-day window holds 3 sale transactions totalling 20,000 shares and $22,000,825.98, by 2 sellers, all 3 of them officer sales. Across the last year the record holds 42 sales totalling 187,216 shares and $206,140,410.12, by 8 sellers, every one an officer sale; across the full record, 87 sales totalling 302,625 shares and $328,018,075.72, by 9 sellers, 85 of the 87 of them officer sales. The site's own insider aggregate, compiled over the same 90-day window, matches the full parse exactly. We assign no motives; this is a register of sales with an empty purchase column, and this audit describes it as exactly that.
Lens 4 — Congress: five sales, no purchase, no member counted. The combined record (as of October 3, 2026) carries zero purchases and five sale transactions, with no most-recent purchase date, no party recorded, and a member-count field of zero. The House aggregate carries the same five sales; the Senate aggregate has no BlackRock row at all. This audit reports the aggregate as it stands rather than reconstructing filers it does not name.
Lens 5 — the 5% register: two filings, all passive, one name chain. Our full parse holds exactly 2 SC 13D/G filings — one SC 13G and one SC 13G/A amendment, with no SC 13D-family filing at all — 2 reporting-person rows across 2 names, most recently filed April 27, 2026, matching the site aggregate's ticker-keyed row on every headline field. The register's maximum is Vanguard Capital Management reporting 10,700,618 shares (6.87%) as of March 31, 2026. The chain changes reporting entity as filed: The Vanguard Group reports 0 shares (0.0%) as of March 13, 2026, and Vanguard Capital Management reports the 6.87% position as of March 31, 2026. There is no activist filer in this register at all.
Lens 6 — short interest: 2,040,079 shares, well under the peak. As of September 15, 2026 — the most recent of 137 FINRA settlements since January 15, 2021 — 2,040,079 shares were sold short, up 6.74% from the prior settlement. The series maximum, 3,564,903 shares on October 31, 2022 — verified by a maximum query over the whole series — leaves the latest 42.8% below it. The last five settlements read 2,095,185, 2,176,024, 1,813,402, 1,911,216 and 2,040,079. Against the year-ago 2,130,051 shares the latest is down 4.2%; against the June 30, 2026 settlement of 2,073,854 it is down 1.6%. Against 154,926,181 shares outstanding, it is 1.32% of the share count, at 4.03 days to cover.
The Gap
The narrative describes the centre of global capital: $15.49 trillion under management, $205 billion of net inflows in a quarter, adjusted earnings per share up 38%, and a stock that had gone nowhere for a year. The filings describe who held the stock itself before any of that was public, and the two ownership lenses point in opposite directions. The full market held 119,228,122 reported shares at June 30, up 16,124,184 shares (+15.64%), as its filer count rose by 27 to 2,308. The tracked cohort held 868,402 shares and cut 31.90% of them: three holders decreased, the largest single cut was Cantillon's 95.4%, and the only increase in the whole cohort was the top holder's 6.5%. The 5% register holds no activist at all — one passive chain whose reported maximum, 6.87%, dates to March. Insiders have recorded no open-market purchase in the parsed record against 87 sales, and sold $22,000,825.98 in the last 90 days. The borrow, at 2,040,079 shares and 1.32% of the share count, is a little over half its October 2022 peak. One plausible reading is that broad, passive accumulation carried the register while the tracked cohort concentrated into a single name and the building's own officers sold into the same quarters. The record supports each clause separately; it does not say which side the next quarter favours.
What Would Change the Picture
Nothing above is a recommendation. It is a record. These filings would change the description:
- 1. The 2026Q3 13Fs (filing window closing mid-November 2026). The cohort held 868,402 shares at June 30 — six holders, 67.0% in ValueAct Capital's position. ValueAct adding or trimming moves this lens on its own; so does any rebuild of Cantillon's position, cut 95.4% in the second quarter.
- 2. A first insider purchase — the record currently has none. The parsed record holds zero purchase transactions across 190 filings, in every window. A single purchase breaks a register that currently has an empty column.
- 3. A fresh Vanguard print, or any SC 13D at all. The register's latest filing is dated April 27, 2026 and reports 6.87% as of March 31, 2026; every filing in the parse is passive. An activist 13D would be this lens's first.
- 4. Whether the borrow keeps drifting, or rebuilds toward its 2022 level. Short interest stands at 2,040,079 shares, 42.8% below the series maximum of 3,564,903. A reading back above the June 30 print of 2,073,854 extends a rebuild; a reading below the series minimum of 1,198,013 sets a new series low.
- 5. A first congressional purchase, or any Senate print. The combined record holds no purchase and five sales, all carried by the House aggregate. A purchase by any member gives this lens its first entry in that column.
Until one of those prints, the record describes a stock held by six of our 83 tracked superinvestors — 868,402 shares, two-thirds of it one holder — whose insiders have never bought a share in the parsed record, whose 5% register is entirely passive, and whose borrow sits well below its 2022 peak.
As-of & Limits
The lenses rest on different clocks, none live: 13F is a June 30, 2026 snapshot published up to 45 days later; Form 4 runs through October 2, 2026; Congress through October 3, 2026; 13D/G through the April 27, 2026 filing; short interest through September 15, 2026; our price file ends October 2, 2026. Two limits are specific to this name. First, the October 14 earnings — the reason for the search interest — postdate every lens here, and the earnings-day price move is known to this audit only from outside coverage, not from our own price file, so nothing in the tape yet reflects positioning after the results. Second, BlackRock reports under two CUSIPs: the by-ticker totals in this audit combine the current CUSIP and a legacy one, and the congressional aggregate's member-count field reads zero even though it carries five sale transactions — both are reported here exactly as the collections carry them.
Related reading: Twelve of 83: One Holder Is 47.7% of the Superinvestors' Johnson & Johnson Stake. Its Insiders Have Bought Once. — Filing Tape #77; Five of 83: Viking Is 70.9% of the Superinvestors' Morgan Stanley Stake. Its Insiders Have Never Bought a Share. — Filing Tape #76; Ten of 83: One Holder Is 60.7% of the Superinvestors' CVS Health Stake. Its Insiders Filed Nothing in 90 Days. — Filing Tape #75. BlackRock's own page: BlackRock (BLK) on GetCoattail.
Methodology and data notes
- Superinvestor lens: 83 managers collected directly from SEC EDGAR Form 13F (managers_13f collection), positions as of June 30, 2026; BlackRock identified by CUSIP 09290D101 (current) and 09247X101 (legacy). Six distinct managers hold long positions totalling 868,402 shares, all of them on the current CUSIP; there are no option rows for this name in the collection. The direction count on the collection's labels, across the long rows, is three DECREASED (Bill Nygren - Oakmark Funds, Hillman Capital Management, William Von Mueffling - Cantillon Capital Management), two UNCHANGED (Dodge & Cox Funds, Thomas Gayner - Markel Group) and one INCREASED (ValueAct Capital); the collection's exit list carries no BlackRock row. Quarter-to-quarter cohort totals (1,275,195 long shares at March 31, in 6 rows; 868,402 long shares at June 30, a change of −406,793 shares or −31.90%) are from the site pipeline's holdings files on the same CUSIP basis in both quarters, and the pipeline's second-quarter totals match the EDGAR collection exactly on both shares and value (differences of 0 shares and $0). ValueAct Capital's share of the cohort is 67.0% = 581,700 / 868,402. Cantillon Capital Management's quarter move, 453,282 shares at March 31 to 20,873 at June 30 (−432,409 shares), is larger than the cohort's net change because ValueAct Capital added 35,600 shares (546,100 to 581,700) in the same quarter.
- Full-market lens: SEC Form 13F Data Sets full-market aggregation. The primary table is the full13f collection's by-ticker file (holders = distinct filers reporting the CUSIPs; 2,305 reported long positions out of 2,308 filers). BlackRock reports under two CUSIPs, 09290D101 (current: 2,281 filers, 119,101,952 shares, $114,905,004,154 reported) and 09247X101 (legacy: 29 filers, 126,170 shares, $111,416,242 reported), and the backfill fixtures' by-CUSIP rows sum to the by-ticker row exactly on shares, reported value and prior value; their holder counts sum to 2,310 against the by-ticker file's 2,308, a difference of 2 filers who report both CUSIPs and are counted once in the by-ticker file. The by-ticker file's entered/exited fields (1,714 and 1,687, a net of +27 that matches the change in holder count) are gross flows, so this audit headlines the net change. Reported-value caution: the aggregate value ($115,016,420,396 over 119,228,122 shares) implies $964.68 per share against a June 30, 2026 close of $961.56 in our price file, a gap of +0.3% — printed here as found. The aggregate sums the VALUE of every information-table row — including put and call option rows — while the share count covers long common-stock rows only, so we headline filer and share counts and label dollar values "reported."
- Insider lens: full-parse Form 4 aggregation (agg_by_ticker), record as of October 2, 2026 (190 filings). Sale and purchase counts are transaction-code counts (S and P) in non-derivative rows; grants and exercises are not counted as purchases, and one filing can contain many transaction rows. Purchase transactions total zero in the full parsed record — zero in the 90-day window (July 5 to October 2, 2026), zero in the one-year window and zero across the record, with zero officer purchases in every window. Sale transactions total 3 in the last 90 days (20,000 shares, $22,000,825.98, 2 sellers, all 3 of them officer sales), 42 in the last year (187,216 shares, $206,140,410.12, 8 sellers, all 42 officer sales) and 87 across the parsed record (302,625 shares, $328,018,075.72, 9 sellers, 85 of the 87 officer sales). The site's insider aggregate (compiled as of October 14, 2026, over a 90-day window) matches the full parse's 90-day window exactly on purchases (0), sales (3), sellers (2) and sale value ($22,000,825.98). The full-parse aggregate's sale-value totals imply $1,100.04 per share for the 90-day window, $1,101.08 for the one-year window and $1,083.91 for the full record, each inside the traded price range of its window on our price file ($990.34 to $1,182.84 for the 90-day window, $922.90 to $1,202.59 for the one-year window, and $531.10 to $1,202.59 across the price file), so the sale totals are cited as figures in this article. "Never bought" in this audit means zero purchase transactions in the parsed Form 4 record we maintain; it is a statement about that record, not about any individual's complete history.
- 13D/G lens: full-parse SC 13D/G parsed filings (2 filings matching issuer CIK 2012383 on CUSIP 09290D101 — a search of the parsed collection on the legacy CUSIP 09247X101 returns no further filings — 2 reporting-person rows across 2 names as filed: one SC 13G and one SC 13G/A filing, the latter an amendment, with no SC 13D-family filing), filings through April 27, 2026. The site aggregation carries this name under a ticker-keyed row; that row (2 filings, 0 D-filings, 2 G-filings, 1 amendment, 2 reporters, latest date April 27, 2026, maximum 6.87% and 10,700,618.0 reported shares) matches the parsed filings on filings, form mix, amendments, latest date, maximum and reported-share total. The parsed reporting-person rows sum to 10,700,618.0 shares, but that total sums reporting-person rows across different dates, so it is not used as a stake figure in the article. The Vanguard chain (The Vanguard Group printing 0 shares at 0.0% as of March 13, 2026, filed March 26, 2026 as SC 13G/A; Vanguard Capital Management printing 10,700,618 shares at 6.87% as of March 31, 2026, filed April 27, 2026 as SC 13G) is reported as filed, under the names exactly as they appear. The parsed coverage for this issuer holds these 2 filings; a 5% holder that has not filed in the covered window would not appear here.
- Congress lens: Senate PTR archive and House PTR archive as maintained on this site. The combined record (as of October 3, 2026) carries zero members on its member-count field, zero purchase transactions, five sale transactions, no most-recent purchase date and no recorded party; the House aggregate (as of October 3, 2026) carries the same figures; the Senate aggregate has no BlackRock row at all. The combined figures equal the House figures, the Senate contributing no row. This audit reports the aggregates as they stand — including the zero member count alongside five recorded sales — and does not reconstruct individual filers beyond what the aggregates carry.
- Short interest lens: FINRA Equity Short Interest files (biweekly settlement dates), collected directly from FINRA's public distribution. The published series covers 137 settlements from January 15, 2021 (first settlement in the series) to September 15, 2026. The latest reading is 2,040,079 shares on September 15, 2026, up 6.74% from the prior settlement (1,911,216 on August 31, 2026). The series maximum is 3,564,903 shares on October 31, 2022 (verified by a maximum query over the series, not read off the latest row), so the latest reading sits 42.8% below the maximum. The year-ago settlement (September 15, 2025) printed 2,130,051 shares, so the latest reading sits 4.2% below a year ago. The series minimum is 1,198,013 shares on November 15, 2023. The June 30, 2026 settlement printed 2,073,854 shares, so the latest reading sits 1.6% below the 13F snapshot date's borrow. FINRA publishes each settlement about two weeks after the fact, so the October price action is not yet in this series. The share-count ratio (1.32%) uses the fundamentals file's shares-outstanding figure below.
- Fundamentals note: our fundamentals collection carries BlackRock's revenue of $24,216,000,000, net income of $5,553,000,000 and assets of $169,998,000,000, each labelled fiscal 2025 in the file. The file is marked ok for this name, with no missing fields: shares outstanding of 154,926,181 (as of April 30, 2025 in the file, sourced in the file to the share count) and a file-computed market value of $167,230,425,103.30. The file does not flag the issuer as a foreign private issuer, and it carries SIC 6211, Security Brokers, Dealers & Flotation Companies. The file's price for the name is $1,079.42 as of October 6, 2026; our daily-close file ends October 2, 2026 at $1,059.63, and we keep the two files' figures separate rather than blending them.
- Prices: our own daily-close file for BlackRock through October 2, 2026 ($1,059.63 close, −1.0% year to date on that file; 252-session closing high $1,202.59 on October 15, 2025, so the last close sits 11.9% below it; 252-session closing low $922.90 on March 12, 2026, so the last close sits 14.8% above it; closes of $961.71 at March 31, 2026 and $961.56 at June 30, 2026, a second-quarter change of −0.0%; change from June 30 to October 2 of +10.2%; change from the September 30, 2025 close of $1,165.87 of −9.1%). The series in our price file begins June 1, 2021 at $876.91 and holds 1,342 rows.
- Market context sources: Google Trends United States list via a trends mirror (checked October 15, 2026; its top ten entries were non-stock topics, so the selection moved to the next source); MarketBeat Trending list (checked October 15, 2026; its top ten names were all already audited in this series or already set aside for missing lenses); Barron's October 14 market-movers coverage (checked October 15, 2026; among the names it walked through, BlackRock was the highest-ranked name not yet audited in this series and not previously set aside); third-quarter 2026 results reported October 14, 2026 (adjusted earnings per share of $15.93, up 38% year over year; revenue of $7.75 billion, up 19%; net inflows of $205 billion; assets under management of $15.49 trillion, up 15%), as carried by the company's results coverage in MarketWatch/Dow Jones and cross-checked against Zacks and Seeking Alpha coverage, checked October 15, 2026; the $14.32 consensus figure, the shares' 3% rise in early New York trade and the stock's 0.4% year-to-date decline heading into Wednesday, as carried by the same MarketWatch/Dow Jones coverage, checked October 15, 2026. Figures we could not confirm against two sources were left out; the external items above are reported speech from those outlets, not GetCoattail measurements.
- BlackRock is in the GetCoattail stock-page universe: BlackRock (BLK) stock page. Series data: blk_lens_data.csv · blk_short_interest_series.csv. Earlier audits: Johnson & Johnson · Morgan Stanley.
Past patterns are not a promise of future results. For education only — not investment advice.
This article describes public filings as of the dates stated. It is not investment advice and makes no recommendation. Filings lag reality: 13F positions are as of June 30, 2026, and later trading is not yet public.
Revision history
- v1.0 — October 15, 2026: first publication.