Eleven of 147: Winslow Is 34.3% of the Superinvestors' Arista Stake. Its Insiders Have Never Bought a Share.

GetCoattail Research — The Filing Tape #136. Arista Networks sits on Zacks.com's most-searched list, and the filings show a register that broadened in the June quarter while its own insiders kept a perfect one-way record: 11 of the 147 superinvestors held the stock at June 30, 2026, totalling 10,146,281 shares — Winslow Capital Management alone is 3,484,991 of them, 34.3% of the tracked stake, after raising its position 68.7%. The verified continuing holders added 21.1% between them. Against that, the parsed insider record holds no purchase at all — zero buys in 217 filings, in any window — against 901 sales worth $2,457,048,179.99.

The Hype

Arista's attention this month is search-driven. The stock has been one of the most searched-for stocks on Zacks.com lately, in a Zacks trending-stock note dated October 19, 2026. Zacks Our price file shows what searchers are looking at: a stock that ran hard into the autumn. Arista rose 38.4% in the second quarter, from $122.78 on March 31 to $169.88 on June 30, and kept going — $207.35 by October 2, up 22.1% since quarter-end, up 58.2% year to date, and just 1.5% below its 252-session high of $210.50, set on August 12. A most-searched listing on a stock sitting near its high: the filings answer who held this name through the run, who added, and who has been selling into it.

The Tape

For Arista Networks — the one hundred and thirty-sixth Filing Tape audit — the tape shows a tracked register that grew on both verification and new money, a full market that added 259 filers, an insider record with no purchase in any window, a one-member House register, a single passive 5% print, and a borrow that has fallen more than a third since quarter-end.

Lens 1 — the superinvestors: eleven holders, verified growth, and a divided register. We track 149 managers whose 13F portfolios we collect from SEC EDGAR — 147 are in the collection (144 at a June 30 period-end, 3 early filers at September 30, none holding this name at September 30, so there is no period split) — and the June 30, 2026 register for the common stock (CUSIP 040413205) is 11 distinct managers holding 10,146,281 shares worth $1,724,266,629, long only, with no option rows: 4 are labelled INCREASED, 5 DECREASED and 2 are NEW, with one exit during the quarter. Winslow Capital Management is the register's largest holder: 3,484,991 shares worth $592,030,271 — 34.3% of the tracked stake — at a 2.04% portfolio weight, labelled INCREASED +68.7% (filed August 13, 2026). The next holders are Bristol (John W. Bristol & Co.) (2,196,682 shares, 21.7% of the cohort, DECREASED -4.2%, at a 5.52% weight), Disciplined Growth Investors (1,788,304 shares, DECREASED -1.3%, at a 5.14% weight), Sustainable Growth Advisers (909,167 shares, one of the two NEW holders), Atalanta Sosnoff Capital (472,263 shares, INCREASED +51.0%), DJE Kapital (462,830 shares, INCREASED +359.0%), Francois Rochon - Giverny Capital (339,892 shares, DECREASED -19.7%), W.H. Reaves & Co. (312,537 shares, DECREASED -24.7%), Thornburg Investment Management (115,902 shares, DECREASED -31.2%), Tortoise Capital Advisors (56,928 shares, INCREASED +84.0%) and Lee Ainslie - Maverick Capital (6,785 shares, the second NEW holder). The top two holders together are 56.0% of the tracked stake. The quarter's change verifies row by row for all nine continuing holders under two register methods that agree exactly (methodology): those nine held 7,620,310 shares at March 31 and 9,230,329 at June 30 (+21.1%). One holder exited during the quarter (Sands Capital Management, 2,698 shares at March 31), and the full register reconciles with no residual: March 31, 7,623,008 shares (the verified continuing holders' 7,620,310, plus the one exit's 2,698); June 30, 10,146,281 (the verified 9,230,329, plus the two new holders' 915,952) — a register-wide rise of 33.1%. Ten of the eleven rows imply $169.88, the June 30 close, exactly; DJE Kapital's row implies $171.21 (methodology). 13F figures are as of June 30, 2026, published up to 45 days later.

Lens 2 — institutions: 259 more filers, and 15.44% more shares. At June 30, 2026, 2,270 institutions reported positions, up 259 from 2,011 at March 31 (+12.88%); 2,259 are long. Reported shares rose 15.44% to 890,496,598 (+119,072,859 shares), and reported value rose 63.50% to $149,109,638,170, labelled "reported" because the aggregate includes option rows (methodology), in a quarter when the price rose 38.4%. Flow counts agree (1,731 entered, 1,472 exited, net +259). The by-ticker aggregate sums two CUSIP lines — the common-stock line and a small second line (CUSIP 040413106, 19 holders, 673,954 shares, 0.08% of the share total) — and the share and value sums across the two lines match the aggregate exactly (methodology).

Lens 3 — insiders: no purchase in the record, against 901 sales. The parsed Form 4 record holds 217 filings through October 2, 2026. Purchases total 0 transactions in every window — the last 90 days, the last year, and the full record alike — by 0 buyers, and the officer-purchase count is 0 in every window too. Sales are the entire record: 901 sales in the full record, 16,326,767 shares for $2,457,048,179.99, by 10 sellers, 609 of them officer sales — 577 of those sales fall in the last year (7,553,492 shares for $1,357,900,064.18, by 8 sellers) and 278 in the last 90 days (4,490,316 shares for $871,033,330.94, by 7 sellers). The sales imply $193.98 per share in the 90-day window, $179.77 in the one-year window and $150.49 across the full record — every cited figure sits inside its window's close range on our price file (methodology). The site's insider aggregate, which runs to a later date on a different 90-day window, prints different counts but agrees on the fact that carries this lens: zero purchases, seven sellers (methodology).

Lens 4 — Congress: one House member, one purchase. The combined record and the House aggregate (both as of October 3, 2026) carry the same picture: 1 member, from the Republican party, with 1 purchase and 0 sales, the purchase dated July 10, 2026. The Senate aggregate (as of October 1, 2026) carries no row for this name. The aggregates record counts and dates, not amounts.

Lens 5 — the 5% register: a single passive filing, maximum 6.25%. Our full parse holds 1 SC 13D/G filing matching the site aggregate — 0 SC 13D family and 1 SC 13G family (1 SC 13G, 0 amendments); 1 reporter name across 1 reporter row. That filing is also the maximum and the latest: Vanguard Capital Management printed 78,571,406 shares at 6.25% as of March 31, 2026 (filed April 29, 2026, SC 13G). A second parsed file under the name's secondary CUSIP prints 0 shares and sits outside the aggregate by definition (methodology).

Lens 6 — short interest: down more than a third since quarter-end, still above a year ago. The latest FINRA settlement, September 15, 2026, records 13,245,323 shares sold short — 1.05% of the 1,261,224,648 shares outstanding — at 3.04 days to cover, down 8.72% from the prior settlement. The series peak across all 137 settlements is 24,334,344 shares on May 15, 2025, and the latest reading sits 45.6% below it and 38.8% below the June 30, 2026 settlement (21,632,457 shares), while standing 5.8% above the year-ago settlement (12,519,594 on September 15, 2025). The recent path runs 21,632,457 (June 30), 19,887,856 (July 15), 12,815,409 (July 31), 12,873,977 (August 14), 14,510,842 (August 31) and 13,245,323 (September 15) — three falls and two rises, with the step down concentrated in the second half of July. The two steps of 2x or more in the full series both sit on the stock's 4-for-1 split settlements and are split artefacts, not borrow changes (methodology).

The Gap

The narrative arriving this month is a momentum one: a most-searched name up 58.2% year to date and sitting 1.5% below its high. Parts of the June tape back that narrative. The broad market genuinely broadened — 259 more filers and 15.44% more shares — and the tracked cohort grew too, a verified +21.1% among continuing holders plus two new positions worth 915,952 shares between them. But the tracked register is divided underneath the headline: five of its eleven holders are labelled DECREASED, including the second- and third-largest, and the growth leans on Winslow's +68.7% and DJE Kapital's +359.0%. Inside the company there is no division at all. In 217 filings there is not one insider purchase — not in the last 90 days, not in the last year, not in the full record — while 7 sellers sold $871,033,330.94 of stock in the last 90 days alone, into a rising price. Congress is nearly absent: one House purchase is the whole register. The 5% register holds a single passive print at 6.25%. And the borrow has been unwinding since quarter-end, down 38.8% from the June 30 settlement — yet it still stands above where it was a year ago. One plausible reading is that the June filings caught two different tapes at once: institutions arriving in size at the market level, and the people inside the company selling in size at the register level, with no recorded insider buy anywhere to set against either.

What Would Change the Picture

Nothing above is a recommendation. These filings would change it:

• 1. The 2026Q3 13F season (filing window closing mid-November 2026). Winslow Capital Management's verified baseline is 3,484,991 shares — 34.3% of the tracked total. Whether that position is held, added to or cut, whether the five holders labelled DECREASED keep cutting, and whether Sustainable Growth Advisers' new 909,167-share position survives its first quarter would each change this lens.
• 2. A first insider purchase. The record holds 0 purchases in 217 filings — none in the last 90 days, the last year, or the full record — against 278 sales in the last 90 days. A first recorded purchase, by any insider, would change this lens outright.
• 3. A first Senate row, or a broader House register. All recorded congressional trading in this name is one House member's single purchase, dated July 10, 2026. A transaction from any senator, or purchases by additional House members, would change this lens.
• 4. A first SC 13D filing, or a new 5% print above 6.25%. The register's only filing is one SC 13G. A first activist-form filing, or any print above Vanguard Capital Management's 6.25% maximum, would change this lens.
• 5. Short interest back above the June 30 settlement, or a further unwind. The borrow stands at 13,245,323 shares, 38.8% below the June 30, 2026 settlement of 21,632,457 and 45.6% below the May 15, 2025 peak of 24,334,344. A reading above 21,632,457 would reverse the post-quarter unwind; a reading below 12,815,409, the July 31, 2026 print, would extend it to a new recent low.

Related reading: Eight of 147: Flossbach von Storch Is 54.4% of the Superinvestors' IBM Stake — and Quintupled It in Q2. No Officer Has Ever Bought a Share.; Two of 147: One Holder Is 99.1% of the Tracked Zoom Stake — Rubric's Verified Position Rose 176.3% in a Quarter When the Price Rose 7.4%, and Insiders Have Never Bought a Share. Arista Networks' own page: Arista Networks (ANET) on GetCoattail.

Methodology and data notes

• 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 aggregates run through October 3, 2026 (Senate through October 1, 2026); 13D/G through April 29, 2026; short interest through September 15, 2026; the price file ends October 2, 2026. Six limits are specific to this audit. First, the roster expanded before the recent audits — from 85 managers (83 filing) to 149 (147 filing) — so "of 147" counts are not comparable to earlier pieces' "of 83" figures. Second, this name carries no period split in its headline count — all eleven tracked holders sit on a June 30, 2026 period-end and none of the three September 30, 2026 early filers holds this name — and both registers reconcile with no residual, as detailed in Lens 1. Third, the full-market aggregate sums two CUSIP lines for this issuer: the common-stock line (CUSIP 040413205; 2,253 holders, 889,822,644 shares) and a second line (CUSIP 040413106, carried under the ticker ANETEUR in the by-CUSIP file; 19 holders, 673,954 shares). Shares, reported value and prior value sum across the two lines to the aggregate exactly; holder counts sum to 2,272 against the aggregate's 2,270 because two holders appear in both lines (the prior quarter's counts carry the same overlap of two). Fourth, the insider record's "no purchase" statement is a full-record statement — the purchase count is 0 in the 90-day, one-year and full windows alike, in both the full parse and the site aggregate — while the two sources' sale counts differ because their windows differ: the full parse runs through October 2, 2026 on a July 5 – October 2 window (278 sales, $871,033,330.94), and the site aggregate is dated October 20, 2026 on a later 90-day window (224 sales, $644,204,211.21); both print seven sellers. This audit cites the full parse throughout. Fifth, the 5% register's aggregate is keyed to the common-stock CUSIP: one further parsed file, under the secondary CUSIP 040413106 — The Vanguard Group at 0 shares and 0.0% as of March 13, 2026 (filed March 26, 2026, SC 13G/A) — sits outside that aggregate by definition and would change neither the count's maximum nor its share total if included. Sixth, the short-interest series is published as collected and is not split-adjusted: its only two steps of 2x or more (4.027x at the November 30, 2021 settlement, which carries a split flag, and 4.884x at the December 13, 2024 settlement) coincide with the two 4-for-1 splits in our price file (November 18, 2021 and December 4, 2024), so share counts before the December 2024 split are not compared with counts after it anywhere in this audit; every short-interest comparison here sits inside the post-split window. The series carries three revision flags (June 15, 2021, May 31, 2023 and November 15, 2023) and one split flag. Ten of the eleven tracked 13F rows imply the June 30 close of $169.88 exactly; DJE Kapital's row implies $171.21, and the cohort's blended implied price is $169.94. Our price file carries the two 4-for-1 split entries above, neither of which touches any 2026 comparison in this audit; every price statement here is mechanical, a date and a close from that file. The Zacks most-searched listing (accessed October 20, 2026) postdates the 13F snapshot and the short-interest series; none of Zacks' figures are cited here beyond the listing itself, reported as outlet content in The Hype; every price figure here is from our own price file.
• Market context sources: the Zacks trending-stock note on Arista Networks dated October 19, 2026 ("has been one of the most searched-for stocks on Zacks.com lately"). Figures we could not confirm were left out; the external item above is reported speech from that outlet, not a GetCoattail measurement.
• Arista Networks is in the GetCoattail stock-page universe: Arista Networks (ANET) stock page. Series data: anet_lens_data.csv · anet_short_interest_series.csv. Earlier audits: IBM · Zoom.

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 20, 2026: first publication.