GetCoattail Research — Constellation Energy is the largest nuclear power operator in the United States, and in the week ended October 9 it led the trending-stock roundups after Google contracted for 3,590 megawatts of its power and the shares jumped about 12% in a day. The filings describe a register that added shares in a falling quarter while its filer count shrank: two tracked superinvestors hold the stock and raised it 18.23%, the full market added 43,925,761 shares across 20 fewer filers, its insiders have recorded exactly one open-market purchase in the parsed record, one senator bought once and sold twice, and the borrow against the stock peaked on the June quarter-end itself.
Start with the narrative. On October 6, 2026, Google and Constellation Energy announced a power arrangement covering 3,590 megawatts, as reported by Reuters the same day: a 20-year purchase agreement for 890 megawatts of new nuclear output from upgrades to existing Constellation reactors, backed by more than $4.3 billion of investment, with first delivery expected in 2028, plus a separate 15-year supply agreement for another 2,700 megawatts in the PJM grid. Reuters reported the shares up more than 13% intraday on the Tuesday of the announcement, to $304.04; the weekly trending roundup that put Constellation first among the week's attention names put the day's gain at about 12%. The business backdrop, as reported from the company's August 6 earnings, is a second quarter with adjusted operating earnings of $2.55 per share and full-year 2026 guidance raised to $11.50–$12.50 from $11.00–$12.00. The analyst backdrop, as aggregated by 247WallSt on October 1, is a 22-analyst consensus with an average price target of $347.28, a high of $441, 19 Buy or Strong Buy ratings and 3 Holds; on October 7, Markets Insider reported Scotiabank maintaining a Buy with a $355 target. Our own price file, which ends October 2 — before the announcement — puts the last close at $257.49, down 27.1% year to date on that file and 36.3% below the 252-session closing high of $403.95 set on October 15, 2025. Our fundamentals file's later price print, $300.40 as of October 6, is the only figure in our data that touches the announcement week, and we keep it separate rather than blending the two files.
Now the filings. For Constellation Energy — the forty-fourth Filing Tape audit — the tape shows broad accumulation in shares, a thinning register of filers, an insider record that is nearly empty in both directions, and a 5% register whose largest blocks were cut by roughly a third.
Lens 1: the superinvestors — two holders, 136,193 shares, up 18.23%
We track 83 large, mostly long-only managers whose 13F portfolios we collect directly from SEC EDGAR. As of June 30, 2026, 2 held Constellation Energy long — no option rows — totalling 136,193 shares worth $33,826,256. The direction count, on the collection's own labels, is two increased — no new positions, no decreases, no unchanged rows, and no exits for this CUSIP.
Torray Funds holds most of it: 107,742 shares worth $26,759,881, a 3.61% portfolio weight, flagged increased by 17.1% — 79.1% of the tracked cohort's Constellation shares. Dennis Hong's ShawSpring Partners holds 28,451 shares worth $7,066,375, a 3.04% weight, flagged increased by 22.8%. The cohort total moved from 115,193 shares at March 31 to 136,193 at June 30, a change of +18.23%, a difference of +21,000 shares: Torray added 15,716 shares and ShawSpring added 5,284, and the two collections' second-quarter totals match to the share and to the dollar (see methodology). The cohort's implied price, $248.37 per share, matches the June 30 close exactly. The price fell from $279.25 at March 31 to $248.37 at June 30, a change of -11.1%: the tracked register added, on net, into a falling quarter — the opposite geometry from a momentum register.
Lens 2: institutions — 1,856 filers, down 20, shares up 18.22%
Zoom out to the whole 13F market and the June quarter was a narrowing register holding more stock. At June 30, 2026, 1,856 institutions reported positions, down 20 from 1,876 at March 31 (-1.07%), and 1,845 reported long positions. Reported shares rose 18.22%, from 241,129,047 to 285,054,808 shares — 43,925,761 more shares than the prior quarter, spread across fewer filers. Reported aggregate value rose 8.50% to $74,527,429,849; the aggregate includes option rows, so we headline filer and share counts and label dollars "reported" (see methodology). The implied value per share, $261.45, sits 5.3% above the June 30 close of $248.37. Set the two 13F lenses side by side and their share growth is nearly identical — the tracked cohort added 18.23% on shares while the full market added 18.22% — but only the broad register lost filers while it added: the same proportional accumulation, executed by a register that got smaller at the edges.
Lens 3: the 5% register — seven filings, all of them passive, and the largest blocks were cut
Our full parse holds seven SC 13D/G filings for Constellation Energy — two SC 13G originals and five SC 13G/A amendments, and no SC 13D filing at all, 22 reporting persons on a row basis, the most recent filed August 7, 2026. The register's maximum percentage belongs to Vanguard Capital Management: 23,174,480 shares (6.39%) as of March 31, 2026, filed April 29, 2026. A separate reporting person, The Vanguard Group, prints 0 shares (0.0%) as of March 13, 2026 in the same register; we report the rows exactly as filed, under the names exactly as they appear, and do not merge two distinct reporting persons into one holder. The register's most recent filing updates the ECP rows: ECP ControlCo, LLC prints 22,043,724 shares (6.1%) as of January 7, 2026 and then 14,443,227 shares (4.0%) as of June 30, 2026 — a 34.5% reduction on that row — with affiliated rows printed alongside it in both filings, including Energy Capital Partners III, LLC at 11,183,651 shares (3.1%) falling to 7,232,996 shares (2.0%), and ECP Calpine GP, LLC at 8,593,116 shares (2.4%) falling to 5,744,080 shares (1.6%). Capital International Investors prints 17,170,795 shares (5.5%) as of December 31, 2025 and then 11,940,831 shares (3.3%) as of March 31, 2026, a 30.5% reduction. The oldest row is FMR LLC at 14,341,724.85 shares (4.6%) as of December 31, 2024, with Abigail P. Johnson printed in the same filing at the same share count. We report rows as filed and never sum them across the register: the aggregation's total across these rows would add different dates together and present a history as if it were a register total. The structural fact of this lens is again the empty half: seven filings, all passive 13G paper, and not one 13D — no filer in this register has declared an active intent.
Lens 4: insiders — exactly one purchase in the parsed record
The parsed Form 4 record holds 75 filings through October 2, 2026, and it is the thinnest insider tape in this series. Across it, open-market purchases total exactly 1 transaction — 1,500 shares for $417,930.90, by one buyer — and that single purchase sits inside both the last year and the last 90 days: the purchase column outside the most recent year is empty, and none of the record's buying is recorded as an officer purchase. Against that stand 2 sales totalling 4,000 shares and $1,241,580.84, by one seller, both of the 2 recorded as officer sales — and neither sale sits in the last year, whose sale column is also empty. Our site's insider aggregate, compiled as of October 11 over its 90-day window, records the identical single purchase, the same $417,930.90 and a most recent purchase date of August 11, 2026 — a difference of zero transactions and zero dollars against the full parse's 90-day window, a match we note because the two collections more often differ. This is a register with almost nothing in either column: across 75 filings, the open-market record is one purchase and two sales. We assign no motives to any of it; the record's near-emptiness is the fact.
Lens 5: Congress — one member, one purchase, two sales, all in the Senate
Across the congressional record we maintain (combined record as of October 3, 2026), Constellation Energy shows one member, with 1 purchase transaction and 2 sale transactions, the most recent purchase dated August 13, 2026, and the member's party recorded as R. The Senate aggregate (as of October 1, 2026) carries the identical record — one member, one purchase, two sales — and the House aggregate (as of October 3, 2026) carries no Constellation row at all, so the combined record is a Senate record. Congressional disclosures report value ranges rather than amounts, so this lens records direction and counts only; here the counts are as thin as the insider lens, and they lean, by one transaction, to the sell side.
Lens 6: short interest — 11,740,256 shares, and the peak was the quarter-end itself
FINRA's files carry the borrow across 111 settlements, from February 15, 2022. As of September 15, 2026 — the most recent settlement — 11,740,256 Constellation shares were sold short, with days-to-cover of 4.22, up 1.45% from the prior settlement. Against the fundamentals file's 354,307,379 shares outstanding, that is 3.31% of the share count. The series maximum is not in the distant past: it is 12,153,531 shares on June 30, 2026 — the same settlement date the 13F lenses snapshot — which puts the latest reading 3.4% below the peak. Against September 15, 2025, the latest reading is up 64.1% from 7,155,135 shares: the borrow roughly doubled across the year the price fell, and it crested on the quarter-end itself. The series minimum is 3,111,942 shares on May 13, 2022.
The recent settlements run 10,654,877 on July 15, then 10,429,475, 9,408,275, 11,572,494 and 11,740,256 — a dip into mid-August and a rebuild since. Set beside the price file, the geometry is the year's tension in one line: the stock closed at $257.49 on October 2, down 27.1% year to date on that file, while the borrow against it stands within 3.4% of the highest reading the series has ever printed.
The gap, stated plainly
The registers describe a stock the analyst community rates with an average target of $347.28 — with the price down 27.1% this year on our file through October 2 — days before a power contract moved it about 12% in a session, months after its institutions had already moved in opposite shapes. The tracked superinvestors held 136,193 shares at June 30 across two holders, with Torray Funds at 79.1% of it, having added 18.23% in a quarter when the price fell 11.1%. The full market matched that pace almost exactly: 285,054,808 reported shares, up 43,925,761, across 1,856 filers — 20 fewer than the prior quarter. The 5% register printed seven filings, every one of them passive: its maximum row is a 6.39% Vanguard Capital Management print, The Vanguard Group printed zero, the ECP ControlCo row was cut 34.5% and Capital International's row was cut 30.5%, and there is not one 13D. Insiders, across 75 parsed filings, recorded exactly one purchase for $417,930.90 against two sales for $1,241,580.84, neither inside the last year. Congress registers one Senate member who bought once and sold twice. And the borrow, at 11,740,256 shares, peaked on the June 30 settlement itself and remains 64.1% above its year-ago level. One plausible reading is that the registers run on different clocks and different mandates: the accumulation in shares was broad but filer-thinning, the 5% register's legacy blocks were being reduced while its newest maximum was printed by a distinct Vanguard reporting person, its own insiders have left the open-market tape almost blank in both directions, and short sellers built a borrow that crested exactly when the 13F snapshot was taken. The record supports each clause separately; it does not say which register is right.
What would change the picture
Nothing above is a recommendation. It is a record. These are the filings that would change the description:
- 1. The 2026Q3 13Fs (filing window closing mid-November 2026). The tracked cohort held 136,193 shares at June 30 across two holders, after an 18.23% increase in a falling quarter. Whether Torray Funds' 107,742 shares grow, hold or shrink — and whether ShawSpring's 28,451 follow the same direction — is the whole lens.
- 2. Whether a second insider purchase ever prints. The parsed record holds exactly 1 purchase transaction, inside the last year, against 2 sales, neither inside the last year. A second purchase — above all a first officer purchase — would change this lens from a near-blank tape into a two-sided one; continued silence would extend the emptiest insider record in this series.
- 3. A first 13D filing. The 5% register holds seven filings, all passive 13G paper, headed in this window by a 6.39% row and two large blocks cut by roughly a third. A first 13D — any filer declaring active intent — would change this lens from a register of index and legacy positions into something else.
- 4. Whether the borrow falls from its quarter-end peak. Short interest stands at 11,740,256 shares, 3.4% below the series peak it printed on June 30, 2026 and 64.1% above its year-ago level. A fall toward the September 2025 reading of 7,155,135 would unwind the year's build; a print above 12,153,531 would set a new series maximum.
- 5. Whether Congress adds a second member. The congressional register holds one Senate member, with one purchase against two sales and a most recent purchase on August 13, 2026. A second member's print, in either chamber and in either direction, would widen this lens beyond a single name.
Until one of those prints, the record describes a stock held by two of our 83 tracked superinvestors — 136,193 shares, 79.1% of it one holder, both holders having added in a quarter the price fell 11.1% — whose full market added 43,925,761 reported shares across 20 fewer filers in the same quarter, whose 5% register is entirely passive paper in which the largest legacy blocks were cut by roughly a third, whose insiders have recorded exactly one purchase in the parsed record, whose congressional register is one Senate member leaning sell-side by count, and whose borrow peaked on the quarter-end the 13F lenses describe.
Related reading: Four of 83: One Holder Is 73.3% of the Superinvestors' DoorDash Stake. Its Insiders Bought $100,283,387.82 in a Year. — Filing Tape #43; One of 83: The Only Superinvestor in Remitly Added 29.0% in Q2. Short Interest Just Hit a Record. — Filing Tape #42; Zero of 83: The Superinvestors Aren't in IREN — Filing Tape #1. Constellation Energy's own page: Constellation Energy Corp (CEG) 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; Constellation Energy identified by CUSIP 21037T109. Two distinct managers hold long positions totalling 136,193 shares; both reported rows are long (no put or call rows); the direction count on the collection's labels is two increased, and the collection's exit list contains no row for this CUSIP. Quarter-to-quarter cohort totals (115,193 shares at March 31 across two filing rows; 136,193 shares at June 30 across two filing rows; change +18.23%) are from the site pipeline's holdings files on the same CUSIP basis in both quarters, and the pipeline's second-quarter share and value totals match the EDGAR collection's long totals exactly (differences of 0 shares and $0). Torray Funds' share of the cohort is 79.1% = 107,742 / 136,193.
- 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 CUSIP; 1,845 of the 1,856 reported long positions), and its figures match the backfill fixtures' by-CUSIP row for 21037T109 exactly on holders, shares, reported value, prior holders and prior reported value. The by-ticker file's entered/exited fields (1,452 and 1,472, a net of -20 that matches the change in holder count) have no counterpart in the by-CUSIP aggregation, which does not publish them, so this audit does not rely on them. Reported-value caution: the aggregate value ($74,527,429,849 over 285,054,808 shares) implies ≈$261.45 per share against a June 30, 2026 close of $248.37 in our price file, a gap of +5.3%. 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 (75 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 exactly 1 across the parsed record (1,500 shares, $417,930.90, one buyer, none of the record's purchases recorded as an officer purchase) — and that one purchase sits in both the year and the 90 days through October 2, 2026. Sale transactions total 2 across the record (4,000 shares, $1,241,580.84, one seller, both of the 2 recorded as officer sales), none of them in the year through October 2, 2026. The site's insider aggregate (compiled as of October 11, 2026, 90-day window) records the identical one purchase, $417,930.90 of purchase value and a most recent purchase date of August 11, 2026 — a difference of zero transactions and zero dollars against the full parse's 90-day window. "Purchases" in this audit is scoped to this parsed record, whose 75 filings are the coverage stated here.
- 13D/G lens: full-parse SC 13D/G aggregation and parsed filings (7 filings matching CUSIP 21037T109 and issuer CIK 1868275, 22 reporting persons on a row basis: 2 SC 13G originals and 5 SC 13G/A amendments, no SC 13D filings), filings through August 7, 2026. Vanguard Capital Management's row (23,174,480 shares at 6.39% as of March 31, 2026, filed April 29, 2026 — a distinct reporting-person name, reported as filed and not merged with The Vanguard Group), The Vanguard Group's row (0 shares at 0.0% as of March 13, 2026, filed March 26, 2026), ECP ControlCo, LLC's rows (22,043,724 shares at 6.1% as of January 7, 2026, filed January 14, 2026; and 14,443,227 shares at 4.0% as of June 30, 2026, filed August 7, 2026), with affiliated ECP rows printed in the same two filings (Energy Capital Partners III, LLC at 11,183,651 shares at 3.1% and then 7,232,996 shares at 2.0%; ECP Calpine GP, LLC at 8,593,116 shares at 2.4% and then 5,744,080 shares at 1.6%), Capital International Investors' rows (17,170,795 shares at 5.5% as of December 31, 2025, filed February 13, 2026; and 11,940,831 shares at 3.3% as of March 31, 2026, filed May 14, 2026) and FMR LLC's row (14,341,724.85 shares at 4.6% as of December 31, 2024, filed February 12, 2025, with Abigail P. Johnson printed in the same filing at the same share count) are reported as filed, under the reporting-person names exactly as they appear. No rows are summed, because the aggregation's totalSharesReported field (203,421,858.7 shares) adds different dates together. No reason for any change is asserted — the filings themselves are the record.
- Congress lens: Senate PTR archive and House PTR archive as maintained on this site, combined record as of October 3, 2026 — one member, 1 purchase transaction and 2 sale transactions, most recent purchase August 13, 2026, party R. The Senate aggregate (as of October 1, 2026) carries the identical record, and the House aggregate (as of October 3, 2026) carries no Constellation row. Congressional disclosures report value ranges, so this lens records direction and counts only.
- Short interest lens: FINRA Equity Short Interest files (biweekly settlement dates), collected directly from FINRA's public distribution. The published series covers 111 settlements from February 15, 2022 (3,745,942 shares) to September 15, 2026. The latest reading is 11,740,256 shares on September 15, 2026, which sits 3.4% below the series maximum of 12,153,531 shares on June 30, 2026 and 64.1% above the September 15, 2025 reading of 7,155,135; the change from the prior settlement is +1.45%. The latest row's prior-settlement field (11,572,494) matches the prior settlement file's reported figure exactly. The series minimum is 3,111,942 shares on May 13, 2022. FINRA publishes each settlement about two weeks after the fact. The share-count ratio (3.31%) uses the fundamentals file's shares-outstanding figure below.
- Fundamentals note: our fundamentals collection carries Constellation Energy's revenue of $25,533,000,000 labelled fiscal 2025, its net income of $2,319,000,000 labelled fiscal 2025, and its assets of $57,249,000,000 labelled fiscal 2025 — all three fields carry the same fiscal year in the file. The file is marked ok for this name, with no missing fields: shares outstanding of 354,307,379 (as of July 31, 2026, sourced in the file to a dei EntityCommonStockSharesOutstanding count) and a file-computed market value of $106,433,934,489.07938. The file's price for the name is $300.40 as of October 6, 2026; our daily-close file ends October 2, 2026 at $257.49, and we keep the two files' figures separate rather than blending them.
- Prices: our own daily-close file for Constellation Energy through October 2, 2026 ($257.49 close, -27.1% year to date on that file; 252-session closing high $403.95 on October 15, 2025; 252-session closing low $236.50 on July 1, 2026; closes of $279.25 at March 31, 2026 and $248.37 at June 30, 2026, a second-quarter change of -11.1%; change from June 30 to October 2 of +3.7% ((257.49 / 248.37) − 1)). The drawdown from the 252-session closing high is -36.3%, the gain from the 252-session closing low is +8.9%, and the series in our price file begins January 19, 2022 at $42.00.
- Market context sources: the Seeking Alpha / TradingView trending-stocks roundup for the week ended October 9, 2026, published October 11, 2026 (Constellation Energy listed first, on Google's agreement to purchase 3,590 megawatts, with the shares up about 12% on the Tuesday); Reuters, October 6, 2026 (Google contracted for 3,590 megawatts from Constellation Energy, new nuclear accounting for about a quarter of the supply, more than $4.3 billion of new investment by Constellation, a 20-year agreement for 890 megawatts from upgraded reactors with first delivery expected in 2028, a separate 15-year supply agreement for 2,700 megawatts, and the shares up more than 13% intraday to $304.04 on the Tuesday); the company's second-quarter 2026 results as reported August 6, 2026 (adjusted operating earnings of $2.55 per share, full-year 2026 adjusted guidance raised to $11.50–$12.50 from $11.00–$12.00); and the analyst backdrop aggregated by 247WallSt on October 1, 2026 (22 analysts, average price target of $347.28, high of $441, 19 Buy or Strong Buy and 3 Hold), with Scotiabank maintaining a Buy and a $355 target as reported by Markets Insider on October 7, 2026. Figures we could not confirm against two sources were left out.
- Constellation Energy is in the GetCoattail stock-page universe: Constellation Energy Corp (CEG) stock page. Series data: ceg_lens_data.csv · ceg_short_interest_series.csv. Earlier audits: DoorDash · Remitly · IREN.
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 12, 2026: first publication.