RESEARCH — THE FILING TAPE #6

Six of 83: The Superinvestors Doubled Their AMD Shares. Its Insiders Still Haven't Bought.

October 8, 2026

GetCoattail Research — AMD is the AI trade's second engine: a stock that crossed $1 trillion in market value in September, revenue up 50% in a year, and the third most-searched ticker in America this month. We ran it through every filing lens we maintain. For once, the concentrated money agrees with the story — it doubled its share count in a single quarter. The insiders, as in every audit in this series, do not appear on the buy side at all.

Start with the narrative, because the numbers behind it are large. Advanced Micro Devices reported second-quarter 2026 results on August 4: revenue of $11.54 billion, up 50% year over year, with Data Center revenue up 107% to $6.7 billion — about 58% of total sales — on demand for EPYC server CPUs and Instinct AI accelerators. On September 21 the shares closed at a record and the company's market value crossed $1 trillion for the first time. On September 28 AMD announced an $8.2 billion all-stock agreement to acquire World Labs, the spatial-intelligence startup, with co-founder Fei-Fei Li joining as chief scientist. Analyst targets have chased the price: BNP Paribas raised its target from $600 to $960 on October 6, and the published mix that week stood at 39 Buys, five Strong Buys and 11 Holds, with no Sell. In our own price file the stock closed at $633.91 on October 2, 2026 — the highest close in its last 252 sessions, and up 196.0% year to date on that file. AMD was the third most-searched ticker on Benzinga Pro for October, behind only the SPY index fund and Tesla.

Now the filings. GetCoattail tracks the portfolios, trades and disclosures of the investors with the most information about any given company: concentrated superinvestors, institutions as a whole, corporate insiders, members of Congress, and 5% holders. For AMD — the sixth Filing Tape audit, after IREN, CoreWeave, Micron, NVIDIA and Tesla — the headline lens points the opposite way from the last two audits. There, the tracked cohort was trimming. Here, it bought.

Lens 1: the superinvestors — three holders became six, and the share count doubled

We track 83 large, mostly long-only managers whose 13F portfolios we collect directly from SEC EDGAR. As of June 30, 2026, six held AMD. At March 31, on the same pipeline basis, three did. The cohort's combined share count went from 899,902 shares to 1,851,493 shares — up 105.7% in one quarter, in a quarter when the share price itself rose 185.6%, from a $203.43 close to $580.91 in our price file.

Read the six closely. The largest position belongs to Maverick Capital: 976,326 shares worth $567,157,537 — 5.01% of its portfolio, and 52.7% of everything the cohort owns in AMD — increased 44.3% in the quarter. The second position is new: Tiger Global Management entered with 674,727 shares worth $391,955,662 (1.63% of its portfolio). Appaloosa Management, the third sized holder, moved the other way, trimming 10.8% to 197,500 shares. The remaining three holders are small: Mairs & Power with 1,648 shares (down 14.6%), Oakmark Funds new with 875 shares, and Polen Capital new with 417 shares. So the doubling is real but narrow: three new names arrived, one existing holder added substantially, and two of the six positions are under 2,000 shares. For scale, 19 of the same 83 managers hold NVIDIA; AMD's six is the same count as Tesla's — but where Tesla's cohort cut its shares by a third, AMD's more than doubled them.

AMD through six filing lenses
Chart 1: Signal presence by cohort. Superinvestors: 83 managers, 2026Q2 13F (as of Jun 30, 2026). Institutions: full-market 13F aggregation, same date. Insiders: Form 4 record through Oct 2, 2026. Congress: Senate and House PTR record through Oct 3, 2026. 13D/G: filings through Apr 29, 2026. Short interest: FINRA biweekly settlement data through Sep 15, 2026. Source: SEC EDGAR; FINRA; GetCoattail collections.

Lens 2: institutions — breadth up by more than a quarter

Zoom out to the whole 13F market and the sponsorship is broad as well as concentrated. At June 30, 2026, 4,000 institutions reported positions in AMD, up from 3,141 at March 31 — a 27.3% jump in one quarter — and 3,981 of them reported long positions. Reported share counts rose 28.85%, from 908,247,419 to 1,170,260,272 shares. The register churned heavily underneath: 2,509 filers entered and 1,650 left. The dataset's reported aggregate value rose 255.9% to $778,844,959,358; most of that increase is the share price itself, and the aggregate includes option rows, so we treat filer and share counts as the reliable series and the dollar figure as reported (see methodology). One plausible reading is that part of this breadth is mechanical — index baskets and benchmark rebalancing produce filer counts like this without any filer forming a view. But unlike Tesla, where the broad register and the concentrated cohort moved in opposite directions, AMD's two registers point the same way.

Lens 3: the 5% register — passive, and only Vanguard

Two SC 13D/G filings cover AMD, and both are 13G — the passive form. There is not one 13D, the filing an investor uses when it wants something from management. The only sized reporter is Vanguard Capital Management at 7.48% (122,092,206 shares, as of March 31, 2026) — an index complex, filing passively. A separate Vanguard Group amendment reported 0 shares and 0.0% as of March 13, 2026; we record the filing without interpreting the internal reorganisation it appears to reflect. No activist has filed, and no holder outside the index complex appears on this register at all. On a stock that tripled in a quarter, the 5% register is the quietest lens in this audit.

Lens 4: insiders — $108.9 million sold in ninety days, zero bought in a year

In the 90 days through October 2, 2026, AMD insiders filed 28 reports covering 78 sale transactions totalling $108,872,252.27 — 219,838 shares sold by six insiders, all 78 transactions by officers. Open-market purchases in the same window: zero.

Widen the window and the purchase side stays empty. Over the full year through October 2, 2026, the record shows 75 filings covering 219 sale transactions totalling $373,164,565.34 by seven sellers — and zero open-market purchases. Across the entire parsed Form 4 record (128 filings), purchases total exactly two transactions: 13,445 shares worth $1,498,944.20, by a single buyer, both predating the last twelve months, against 255 sale transactions totalling $443,804,782.12. Some selling is mechanical — vesting and tax withholding generate filings regardless of anyone's view — and we assign no motives. But the purchase side has no mechanical explanation: during a year in which the stock rose from a $164.67 closing low (October 3, 2025) to a record close, no AMD insider bought a single share at market price. Our site's separate 90-day insider aggregate matches the full-parse figures exactly: zero buys, 78 sales, $108,872,252.27, six sellers.

Lens 5: Congress — three members, nine buys against two sells

Across the Senate and House transaction record we maintain (as of October 3, 2026), three members of Congress have traded AMD: nine purchases and two sales, with the most recent purchase on July 17, 2026. All of it is in the House record, and all three members are Democrats; the Senate record shows no AMD transactions at all. The counts are small, and congressional disclosures report ranges rather than exact values, so we record direction only. Even with that caution, AMD's nine-to-two buy-sell split is the most buy-leaning congressional record in this series — NVIDIA recorded five members, Micron four, Tesla one, and IREN and CoreWeave none. On this lens, the filings lean the same way as the narrative.

Lens 6: short interest — half its 2021 peak, and drifting down

As of September 15, 2026 — the most recent FINRA settlement date — 39,975,696 AMD shares were sold short: 2.45% of the 1,632,475,042 shares the company most recently reported outstanding, with days-to-cover of 2.13. That is a modest borrow for a stock at a record high.

Short interest in AMD, January 2021 to September 2026
Chart 2: Shares sold short in AMD at each FINRA biweekly settlement, Jan 15, 2021 – Sep 15, 2026 (n = 137 settlements). The series peaked at 89,134,119 shares on Jul 30, 2021 and has since fallen 55.2%. Source: FINRA Equity Short Interest files; GetCoattail collection.

The latest reading sits 55.2% below the series peak of 89,134,119 shares on July 30, 2021, and 4.3% below its year-ago level of 41,767,201 shares. Within 2026 it reached 46,762,536 shares at June 15, then eased to 39,975,696 by September 15, falling 4.16% in the final settlement alone. Whatever scepticism a $1 trillion valuation invites in commentary, it is not currently expressed as a large short position — the borrow has been shrinking while the price has been rising.

The gap, stated plainly

AMD is the first audit in this series where the concentrated-money lens confirms the story instead of contradicting it. The tracked superinvestor cohort doubled its share count in the very quarter the stock rose 185.6%; the full register added 859 filers; Congress leans nine-to-two toward buying; and the short borrow, at 2.45% of shares outstanding, is half its 2021 peak. Two lenses still point the other way, and they are the same two that have pointed that way in every audit: insiders sold $108.9 million in ninety days and have not bought a share in at least a year — the only two purchases in the entire parsed record are old and total under $1.5 million — and the 5% register holds no one but a passive index filer. The filings describe a stock the smart-money cohort joined late and in size, that its own officers have only sold, and that almost nobody is betting against.

What would change the picture

Nothing above is a recommendation. It is a record. These are the filings that would change the description, in the order the data will arrive:

Until one of those prints, the filing record describes the market's second AI engine as newly owned by the concentrated cohort, bought on balance by Congress, lightly shorted — and sold, on the record, by the only people who work there.

Related reading: Six of 83: The Superinvestors Hold Little Tesla — and Cut a Third of It in Q2 — Filing Tape #5; Zero of 83: The Superinvestors Aren't in IREN — Filing Tape #1; 80% Overlap, No Copycat Signal: Congress vs. the Superinvestors. AMD's own page: Advanced Micro Devices (AMD) on GetCoattail.

Methodology and data notes

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

MORE RESEARCH

Six of 83: The Superinvestors Hold Little Tesla — and Cut a Third of It in Q2
Six of the 83 superinvestors we track hold Tesla — one name is 84.8% of the cohort — and the cohort cut its aggregate share count 33.2% in the second quarter while all institutions added 27.9%, insiders filed one report in 90 days with zero purchases in a year, and short interest sits at 1.74% of shares outstanding.
80% Overlap, No Copycat Signal: Congress vs. the Superinvestors
Four of five congressional stock buys land in a stock the superinvestors hold — 688 shared names. But ticker by ticker, how often Congress buys a stock has almost nothing to do with how many managers hold it (ρ = 0.099), and the shared names did not pay better.