Insider Buying Signals, June 8–15, 2026

The June 8–15 window produced roughly $247M in qualifying open-market purchases across eight US-listed entities — nearly twice last week's $127M — after removing three transactions reclassified as structured offerings and one with a same-day offsetting insider sale. 1 The headline is Summit Therapeutics: the two Co-CEOs spent a combined $99.97M on a single day, making it the largest insider purchase cluster in this channel's tracked history. Strip SMMT out and the remaining qualifying volume is roughly $147M — still comfortably above last week's comparable base.

Three structural patterns define this week. First, the SMMT cluster is unusual even by recent standards: same two people, same-day execution, and a 34× escalation from the $2.92M they bought just eight days earlier — against a backdrop of landmark Phase III OS data and a $500M dilutive offering. Second, Robinhood director Malka Meyer completed a third consecutive purchase inside a two-week window, bringing her cumulative to $55.3M across three tranches at declining prices. Third, three entries that appeared on screeners this week — Liftoff Mobile ($60M), Quantinuum ($24.6M), and Borr Drilling ($5.0M) — do not qualify after reclassification review and are excluded from the conviction pool.

† M notation: multiple transactions in one filing; pure open-market classification unconfirmed pending EDGAR verification. All other transactions are Form 4 code-P open-market purchases with no M/D/A annotations. Data: OpenInsider, Finviz. 1

Maky Zanganeh and Robert Duggan, Co-CEOs and 10% owners of Summit Therapeutics (NASDAQ: SMMT), each purchased 3,810,000 shares at $13.12 on June 12, 2026, spending $49,987,200 each — a combined cluster of $99,974,400 in a single trading session. 1 Both filings carry pure code-P classification with no M/D/A annotations. Post-purchase, each Co-CEO holds 610,015,809 shares.

The scale warrants context. This is the fourth time in two years both Co-CEOs have bought on the same date. Their prior synchronized purchases: $5.98M each on September 10, 2025 (at $17.69); $0.50M each on October 21, 2025 (at $18.74, alongside Director Yu Xia's $10M purchase); and $1.46M each on June 4, 2026 (at $14.60). 2 Zero insider sales in the entire two-year tracked history. The June 12 purchase escalates from the June 4 cluster by a factor of 34 — at a price $1.48 lower per share. The Co-CEOs' weighted average cost basis across all four purchases is approximately $15.51 per share; the June 12 price of $13.12 sits roughly 15% below that blended cost.

The purchase arrived ten days after the most significant clinical result in Summit's history. On June 1, Zanganeh and Duggan's team published the HARMONi-6 Phase III data in The Lancet and presented it at the ASCO 2026 Plenary: ivonescimab combined with chemotherapy produced an overall survival hazard ratio of 0.66 versus tislelizumab combined with chemotherapy in first-line squamous non-small cell lung cancer — a 34% reduction in death risk. 3 Median overall survival was 27.89 months versus 23.69 months; the 24-month OS rate was 64.7% versus 48.6%. The company describes this as the first regimen to demonstrate a statistically significant overall survival benefit over an anti-PD-(L)1 plus chemotherapy combination in any Phase III first-line NSCLC trial.

Between the data readout and the $100M purchase, Summit announced on June 9 a $500M underwritten public offering with J.P. Morgan, Goldman Sachs, and Citigroup as joint book-runners, plus a $75M 30-day underwriter option. 4 Proceeds are designated for ivonescimab R&D and general corporate purposes. The offering diluted the float and, based on the sequence of events, appears to have pushed the stock lower: on June 4 the Co-CEOs bought at $14.60; by June 12 the stock was at $13.12 — the offering window created the dip they purchased into. SMMT closed at $14.01 on June 15, +6.8% above the purchase price. 5 Short interest stands at 36.13 million shares, representing 28.21% of the float of 130.62 million shares as of May 29. 5

The PDUFA date for ivonescimab is November 14, 2026. The Co-CEOs are deploying nine-figure personal capital five months before that binary event, at prices below their prior cost basis, immediately following dilutive corporate financing. That combination — escalation, same-day synchrony, post-dilution timing, zero historical sales — makes this the most structurally distinctive signal this channel has recorded.

Track record: 4/4 synchronized purchases across two years, zero sales. Weighted average entry ~$15.51. Current price $14.01 is below that average, meaning the pattern has not yet delivered a paper gain at this cost basis level.

Malka Meyer, Director of Robinhood Markets (NASDAQ: HOOD) and founding partner of Ribbit Capital (an early Robinhood investor), purchased 250,000 shares at $80.74 on June 5, 2026 for $20,184,200 — her third purchase in roughly eight days. 1 The full sequence: $20.02M at $80.39 on May 28, $15.10M at $83.45 on June 3, and this $20.18M at $80.74 — combining for $55.31M at a weighted average of approximately $81.34 per share. 6 Post-purchase, Ribbit-affiliated entities hold more than 8 million HOOD shares.

The directional context matters here. In August 2025, Meyer sold 1,173,808 shares at $103.88, generating $121.9M in proceeds. She also sold 64,951 shares at $49.64 in February 2025. From that seller position, she has reversed to buying $55M at prices clustered around $81 — a spread of roughly 22% below her August 2025 exit. 6 Three purchases in eight days at declining prices is not typical of a portfolio rebalance; the escalating frequency at lower prices is consistent with deliberate accumulation.

The CEO/CFO/CTO selling pattern remains a structural offset, as noted last week. Whether those sales are being made under 10b5-1 auto-plans has not been confirmed from available Form 4 footnotes — the standard caveat applies. 6

Robinhood's June catalysts partially explain the backdrop for the purchase. On June 4, FINRA eliminated the Pattern Day Trader margin requirement — removing the $25,000 account-balance restriction that had limited day trading for smaller accounts and directly addressing a friction point for Robinhood's core retail customer. On June 9, Robinhood Securities was approved as an IPO underwriter, with CEO Vlad Tenev stating: "Becoming an underwriter, and not just a selling group member, is the natural next step to better serve our customers and our issuers. We intend to be disruptive in this space." 7 May operating metrics reinforced the growth narrative: equity notional trading volumes reached $315B (+75% year-over-year), total platform assets hit $377B (a record, +48% YoY), and funded customers reached 27.7M. 7

HOOD closed at $93.19 on June 15 — +15.4% above Meyer's June 5 purchase price in ten trading days. 8 The Q1 2026 miss ($0.38 EPS vs. $0.41 estimate, $1.07B revenue vs. $1.17B forecast) appears to have been the context for the earlier tranches, not the June catalysts.

Track record: Meyer sold $121.9M at ~$104 in August 2025, then bought $55.3M at ~$81 in May–June 2026. Three buys, zero sales in 2026. The trade is a textbook "sell high, buy lower" sequence, now showing a $12.45 per-share unrealized gain from the June 5 entry.

Edward P. Garden, Director of Fortune Brands Innovations (NYSE: FBIN) and co-founder of Trian Fund Management (an activist investment firm), purchased 320,067 shares at $40.60 on June 10, 2026 for $12,994,720. 1 Post-purchase position: 3,944,999 shares (+9% change in ownership from ~3,624,950).

Caveat: This filing carries an "M" notation in OpenInsider, indicating the Form 4 contains multiple transactions and that $40.60 is a weighted average price — not necessarily a single block at a single price. The M notation can indicate an option-exercise component mixed with open-market purchases. Direct EDGAR verification was blocked during the research window (HTTP 403, SEC maintenance). 1 Until the filing is confirmed as pure code-P, this transaction should be treated as likely but not definitively a clean open-market purchase.

Taking the purchase at face value: Garden's full accumulation in FBIN now reads three transactions in three weeks — May 19 ($13.66M at $33.40), May 20 ($2.00M at $34.89), and this June 10 buy at $40.60. Combined total: $28.66M at a weighted average cost of approximately $36.44 per share. 9 That is an activist entry pattern: no prior buying in the two-year tracked window, concentrated accumulation in three weeks, with a resumed purchase after a four-week pause at a price 22% above the initial entry. FBIN closed at $43.22 on June 15 (+6.5% above the June 10 purchase). 10

No company-specific catalyst was identified within the ±14-day window around the purchase. Fortune Brands, which makes cabinet hardware (Master Lock), plumbing products (Moen), and door/security products, reported FY2025 revenue of $4.46B, down 3.16% year-over-year. 10 The stock's 52-week range is $32.34–$64.84; the May–June buying cluster began near the 52-week lows. Trian's 13D filing status for FBIN has not been confirmed from available sources.

Track record: Three purchases, all within five weeks, zero prior buying history. Activist pattern — likely signals an impending 13D campaign or engagement rather than straightforward price conviction. No historical track record to assess yet.

RA Capital Management, L.P., Director and 10% owner of Artiva Biotherapeutics (NASDAQ: ARTV, an allogeneic NK-cell therapy developer), purchased 1,027,722 shares at $7.44 on June 9, 2026 for $7,650,148. 1 Post-purchase position: 17,391,440 shares (+6% change in ownership). Pure code-P, no annotations.

The clinical backdrop: Artiva's lead program, AlloNK, received FDA Regenerative Medicine Advanced Therapy (RMAT) designation for refractory rheumatoid arthritis in early June 2026, and data was presented at EULAR 2026. RMAT designation accelerates the FDA's collaborative development process and is typically granted to therapies showing preliminary evidence of substantial improvement over existing treatments. 11 ARTV's market cap at the time of purchase was approximately $339M (48.6M shares outstanding). The stock closed at $8.54 on June 15, +14.8% above the purchase price.

For context on the accumulation pattern: a separate entity, GC Corp., purchased $16.5M of ARTV at $11.52 on May 11, 2026 — outside this week's window but the same stock, suggesting two distinct institutional holders have been accumulating over the same general period. RA Capital is a healthcare-specialist investment firm with deep biotech analytical capacity; its decision to add here after RMAT designation is a catalyst-driven signal rather than a blind accumulation. 12

Track record: Three purchases in two years at declining prices ($12 IPO area, $11.52, $7.44). RA Capital's sustained buying into a lower price is a mixed read — commitment to the thesis despite paper losses since the IPO.

Michael I. McCabe, Head of Strategy at StepStone Group Inc. (NASDAQ: STEP, a private markets investment platform providing access to private equity, real assets, private debt, and venture capital), purchased 120,000 shares at $41.85 on June 11, 2026 for $5,022,072. 1 Post-purchase position: 3,398,945 shares (+4% change). Pure code-P, no annotations.

The purchase came near a notable operational inflection. StepStone reported FY2026 results on May 20: $38B in gross AUM additions for the year ($14B in Q4 alone), revenue of $1.99B (+69.7% year-over-year), and fee-related earnings of $105M (+12%). 13 The stock's 52-week range is $40.58–$77.80; McCabe bought at $41.85, approximately 1.3% above the 52-week floor. STEP closed at $44.39 on June 15, +6.1% above the purchase. 14

The Head of Strategy title is not typically associated with large insider buying at asset managers — this role sees the firm's deal flow and capital allocation decisions directly. A $5M personal purchase at near-52-week lows after a record fundraising year carries informational weight beyond the dollar amount.

Track record: McCabe was a net seller in 2025, with $31.6M in sales across three transactions at $56–$66. This is his first purchase and represents a seller-to-buyer pivot at prices 37% below his prior exit range. Single buy, limited track record as a buyer.

Michael Alfred, Director of Bakkt, Inc. (NYSE: BKKT, a digital asset platform offering crypto trading, custody, and institutional services), purchased 280,000 shares at $7.75 on June 9, 2026 for $2,170,800. 1 Post-purchase position: 933,476 shares — a +43% increase in his ownership. Pure code-P, no annotations.

For context: Alfred also purchased $4.85M at $8.29 on May 15, 2026. The two buys in under a month combine for $7.02M at a weighted average of approximately $8.06 per share. 15 Bakkt secured Indian regulatory approval for its Transchem investment on June 4, expanding its international footprint. Q1 2026 financials: $243.6M in crypto services revenue, $82.6M cash, no long-term debt. Analyst price targets for BKKT range from $21 to $22 — a substantial premium to the current $8.43 close. 16 Bakkt has been under sustained pressure since its 2021 SPAC-merger debut.

Track record: Two purchases in one month, both in the $7.75–$8.29 range. Mixed, limited history. Also noted: CEO Naheta purchased $1.47M at $8.19 in August 2025 — a third distinct insider who has paid similar prices.

William P. Scully, 10% owner of Prothena Corp (NASDAQ: PRTA, a biotech focused on protein dysregulation diseases including AL amyloidosis and Alzheimer's disease), purchased 125,000 shares at $8.17 on June 11, 2026 for $1,021,225. 1 Post-purchase position: 1,193,000 shares (+12%). Pure code-P, no annotations.

Scully has made five purchases in the past 18 months at declining prices — from approximately $13.26 down to this $8.17 entry — totaling roughly $5.69M. 17 A Novo Nordisk partnership asset received FDA Fast Track designation in the relevant period. The stock closed at $8.25 on June 15, +1.0% above the purchase. 18

Track record: Five buys, zero sales, but prices have declined consistently from the first purchase to the most recent — the commitment has not been rewarded by market price action to date. Lower-conviction speculative classification.

Vineet A. Nargolwala, President and CEO of Brady Corp (NYSE: BRC, an industrial identification and safety products manufacturer), purchased 13,011 shares at $76.86 on June 10, 2026 for $1,000,025. 1 Post-purchase position: 78,393 shares — a +20% increase in his owned shares. Pure code-P, no annotations.

Brady reported Q1 FY2026 EPS of $1.50 and declared a $0.245 quarterly cash dividend payable July 31, 2026. 19 The company completed the acquisition of Honeywell's Safety and Productivity Solutions (PSS) business during the period, adding scale. BRC closed at $82.63 on June 15, +7.5% above the purchase price.

A CEO making a $1M open-market purchase at market price with no options component is a clean, if modest, signal. Prior CEO Michael Shaller was a net seller.

Track record: Nargolwala's first recorded purchase as CEO. Unproven — no historical record to assess.

LFTO (Liftoff Mobile, $60M) — General Atlantic entities General Atlantic Genpar, L.P. and General Atlantic (Lft), L.P. each purchased 1,304,347 shares of Liftoff Mobile at $23.00 on June 5, 2026, for $29,999,981 each. 1 The timing is dispositive: Liftoff Mobile completed its IPO on June 4, 2026 at $23.00 per share, raising net proceeds of $472.4M. 20 General Atlantic has a stockholders agreement with the company and was a pre-IPO investor; both entities bought on the IPO's first trading day at the exact offering price. This reflects IPO allocation, not a subsequent discretionary open-market accumulation.

QNT (Quantinuum, $24.6M) — 11 insiders at Quantinuum Inc., a trapped-ion quantum computing company, all purchased shares at exactly $60.00 on June 5, 2026. 21 The three largest: Director Hal Barron $15M (>999% ownership change — entirely new position), Director Joseph Jimenez $4M (>999% ownership change), Director Manish H. Bhatia $1.2M. A uniform price across 11 separate insiders on a single day is the signature of a directed share transaction — a structured offering or direct placement at a set price — rather than independent open-market buying. QNT also did not appear in OpenInsider's Top 100 for the week, despite the $24.6M total; it was discoverable only via Finviz cross-check. 21 Excluded pending structural verification. (The individual buyers — particularly Barron, the former Chief Science Officer of GSK and R&D president at Alphabet — may be genuinely high-conviction holders; the transaction structure, not the investors, is the disqualifying factor here.)

BORR (Borr Drilling, ~$5M) — Director Tor Olav Troim purchased 1,063,000 shares at $4.70 on June 9 for $4,996,100. That same day, a second Borr Drilling director — Mordehachvili Thiago — sold 8,000,000 shares at $4.70, generating $37,600,000. 21 A $5M buy occurring simultaneously with a $37.6M sale at an identical price from another director is not a conviction signal. The M notation on Troim's filing adds further uncertainty about the purchase structure. Excluded.

NCLH's 8-insider cluster from May 7 through June 1 — which included CEO John Chidsey's first buy in a two-year window ($2.5M at $16.37) and Director Stephen Pagliuca's (of Bain Capital) $25M single purchase — saw no new Form 4 filings this week. The cluster has accumulated $29.2M from eight separate insiders; NCLH has closed at $19.43 as of June 15, up 18.7% from Chidsey's May 22 purchase price. 22 The cluster was the subject of last week's edition; the pause does not invalidate the prior signal.

SVRE (Visionwave Holdings / VWAV): this ticker is permanently excluded from all signal counts. OpenInsider shows insider "buy" values reading exactly 2,147,483,647 — the maximum value of a signed 32-bit integer — which is a data overflow artifact in the SEC filing's XML, not an actual transaction. 1 Any screener result for SVRE should be discarded without review.