Impactive's VAC sale and Chernett's CVRx ask lead the August 18–25 whale tape (2026)

Data cutoff: SEC availability through Tuesday, August 25, 2026, 08:00 CT. The cleanest read from the August 18–25 filing window is not a broad buy wave. It is a cluster of dated open-market sales, one activist letter that puts a sale on the agenda, and a set of passive threshold maps that should not be confused with fresh conviction buys.

The quick scan

Manager or holder	Ticker	What became public	Directional read
Impactive Capital	VAC	Sold 750,000 shares at $111.49 on Aug. 19; still holds 9.8%	Confirmed open-market sell; filer calls it portfolio rebalancing
Montanova / Averill	MANE	Sold 750,000 shares at $107.25 on Aug. 19; exercised 300,000 warrants at $0.00001 on Aug. 20; holds 8.8%	Confirmed open-market sell plus near-zero warrant exercise
5AM Ventures	SKYE	Sold 300,000 shares at a $0.38 weighted average on Aug. 18; holds 30.2%; committed up to $10 million in Redx-linked financing	Small open-market sell next to a larger financing commitment
Chernett Guardian Capital	CVRX	New 5.5% Schedule 13D; Aug. 24 letter asks the board to prioritize a sale process	Activist control signal, not a copy-trade buy
Millennium / Englander	TNYA	5.2% Schedule 13G after an Aug. 17 event date	Passive ownership map
Millennium	CAPR	4.9% Schedule 13G; crossed above 5% on Aug. 17, then fell to 5% or less	Threshold map, not a clean buy or exit
Jane Street	CISS	7.2% Schedule 13G after an Aug. 13 event date	Passive ownership map
Jane Street	CDTG	5.1% Schedule 13G after an Aug. 17 event date	Passive ownership map
Starboard	BILL	Still 10.1%, including cash-settled forwards; no trades in the prior 60 days	Share-count artifact, not a fresh trade
CK Amarillo / Hertz founder group	HTZ	50.9% stake with an Aug. 20 voting agreement that caps excess votes above 45%	Control / governance special situation
Mithril	BKSY	Amended filing shows 0% after June pro-rata LP distributions	Exit mechanics, not an open-market sale

The table ranks what a retail trader can act on now: first the dated sells, then the activist letter, then the passive maps and special situations. It does not treat every percentage as a purchase or a sale.

Impactive's Marriott Vacations sale is the week's cleanest tape

Impactive Capital's Amendment No. 4 to Schedule 13D for Marriott Vacations Worldwide reports beneficial ownership of 3,380,818 shares, or 9.8% of 34,395,320 shares outstanding. The amendment was accepted by EDGAR on August 20, 2026. See the VAC Schedule 13D/A filing.

Schedule A of the same filing lists one open-market sale in the prior sixty days: 750,000 shares sold on August 19, 2026 at $111.49 per share, or about $83.6 million before commissions. Impactive states that the sale was made for portfolio-rebalancing reasons and “does not reflect any change in the Reporting Persons’ view of the Issuer’s prospects.” That wording matters. The trade is confirmed; the economic motive is the filer’s own account, not an independent thesis a reader can verify from the form alone.

Montanova cut Veradermics while exercising cheap warrants

Montanova’s Amendment No. 2 for Veradermics (MANE) reports 3,718,970 shares, or 8.8% of the company after counting 41,780,136 shares outstanding plus 300,000 shares issuable on warrant exercise. The amendment was accepted on August 21, 2026. See the MANE Schedule 13D/A filing.

The transaction schedule is unusually clean. On August 19, Averill Master Fund sold 690,601 shares and Averill Madison Fund sold 59,399 shares, both at $107.25, for a combined 750,000-share sale worth about $80.4 million. On August 20, the same funds exercised warrants for 149,000 and 151,000 shares at $0.00001 per share. The package is therefore a large cash sale plus a near-zero-cost share top-up, not a simple exit or a simple add.

5AM’s Skye sales sit next to a Redx financing commit

5AM Ventures’ Amendment No. 5 for Skye Bioscience reports aggregate beneficial ownership of 11,273,407 shares, or 30.2% of 35,421,413 shares outstanding. The amendment was accepted on August 18, 2026. See the SKYE Schedule 13D/A filing.

On August 18, affiliated 5AM funds sold a total of 300,000 shares in the open market at a weighted-average price of $0.38, or about $114,000. That sale is tiny next to the position size. The more important forward-looking disclosure is that 5AM VII committed to buy up to $10 million of Skye securities in a concurrent financing of up to about $72.9 million tied to Skye’s planned acquisition of Redx Pharma. The same amendment also notes that a Rule 10b5-1 plan was terminated on August 14. The usable signal is mixed: a small market sale, a larger financing commitment, and a control-level ownership map that still needs the deal path to clear.

Chernett’s CVRx filing puts a sale process on the agenda

Chernett Guardian Capital Management’s new Schedule 13D for CVRx reports 1,461,750 shares, or 5.5% of 26,641,597 shares outstanding, with an aggregate purchase price of $7,995,772. The filing was accepted on August 24, 2026 and supersedes an August 14 Schedule 13G. See the CVRX Schedule 13D filing.

Attached to the filing is an August 24 letter asking the board to engage an independent financial advisor and to pursue strategic alternatives, “with a sale of the Company as a priority.” That is activist language with a clear preferred outcome. It is not, by itself, evidence that a buyer exists or that common shareholders will get a premium. The same reporting group also amended its Neuronetics (STIM) Schedule 13D the same day to 10,602,988 shares, or 13.92% of 76,197,222; that update mainly refreshes the percentage after a larger share count and continues a campaign already on this channel’s watch list.

Millennium Management and Israel A. Englander reported a 5.2% passive stake in Tenaya Therapeutics: 11,581,565 shares after an August 17 event date, with the Schedule 13G accepted on August 24. See the TNYA Schedule 13G filing.

A second Millennium Schedule 13G for Capricor Therapeutics reports 2,857,387 shares, or 4.9%. The filing says the position exceeded 5% on August 17 and then fell to 5% or less. See the CAPR Schedule 13G filing. That is a threshold map. Without a transaction schedule, a reader cannot treat it as either a confirmed buy or a completed exit.

Jane Street appeared in two passive filings. Its C3is Schedule 13G reports 937,330 shares, or 7.2%, after an August 13 event date. See the CISS Schedule 13G filing. Its CDT Environmental Schedule 13G reports 154,512 shares, or 5.1%, after an August 17 event date. See the CDTG Schedule 13G filing. Both are ownership maps, not dated open-market conviction trades.

Starboard’s Amendment No. 3 for BILL Holdings still shows 8,639,900 shares, or 10.1% of 85,276,782, including 1,614,152 shares underlying cash-settled forwards. The filing states that no transactions occurred in the prior sixty days and that the percentage change came from a reduced share count. See the BILL Schedule 13D/A filing. That is the week’s clearest reminder that a rising ownership percentage can be arithmetic rather than buying.

Supplemental special situations

Two control-linked disclosures sit outside the core US-manager open-market tape.

CK Amarillo and related Hertz founder parties reported 181,455,469 shares of Hertz Global Holdings, or 50.9% of 356,451,393. An August 20 amended voting agreement says shares that would otherwise vote above 45% will instead vote proportionally with other stockholders, with a sale-of-control premium-sharing mechanism. See the HTZ Schedule 13D/A filing. The signal is governance and litigation settlement architecture, not a fresh hedge-fund trade.

Mithril’s Amendment No. 4 for BlackSky Technology reports beneficial ownership of zero shares. The change came from June 5 pro-rata distributions of 1,298,328 and 1,030,175 shares to limited partners for no consideration. See the BKSY Schedule 13D/A filing. That is an exit from the reporting group’s books, not evidence of an open-market dump at a disclosed price.

What to follow next

VAC: watch whether Impactive amends again with another Schedule A sale, or whether the remaining 9.8% stays put after the rebalancing language.
MANE: separate the Aug. 19 cash sale from the Aug. 20 warrant exercises before estimating net economic exposure.
SKYE: track the Redx closing and the concurrent financing; the $0.38 sales are secondary to the $10 million 5AM commitment.
CVRX: look for a board response, advisor engagement, or a formal process letter after Chernett’s Aug. 24 sale-priority ask.
TNYA / CAPR / CISS / CDTG: wait for an amendment with a share-count delta before treating any of these passive maps as a trade to copy.
BILL: ignore the percentage move until Starboard reports an actual purchase or sale; the current change is a share-count artifact.
HTZ and BKSY: keep them in the special-situation bucket — voting mechanics and LP distributions, not retail copy trades.

The week therefore favors verification over copying. The actionable work is to follow the dated sale schedules and the CVRx process ask, while keeping passive threshold maps and control mechanics in separate buckets.