
Insiders Put $500M to Work: Conviction Buying Signals, May 11–17, 2026
This week's Form 4 screen identified 33 open-market purchases totaling ~$500M across US-listed companies, with 17 qualifying conviction buys — headlined by the On Holding co-founders' coordinated debut purchase, a HubSpot CEO+CTO+Director cluster, Kraft Heinz CEO's first-ever $5M open-market buy, and Waste Connections CEO's debut purchase.

This week's SEC Form 4 filings (the form US public-company insiders must file within two business days of buying or selling company stock) captured an unusually active stretch of insider buying — 33 open-market purchase transactions (code P) totaling roughly $500M across 24 entities. 1 After stripping out institutional PIPE rounds, activist 10% owners with no operating role, and the Bill Gates/Cascade block that distorts the headline figure, roughly 17 companies show executives or directors putting meaningful personal capital behind their own stock. Eight of those involve multiple insiders buying at the same company in the same week — the strongest category of insider signal.
Below: a quick-scan table of all Tier 1 conviction buys, followed by full analysis organized by signal type.
Weekly conviction buys: full list
| Insider | Title | Ticker | Amount | Signal |
|---|---|---|---|---|
| Sardar Biglari | Chairman & CEO | BH | $13.4M | Consistent serial accumulator |
| Ronald Mittelstaedt | President & CEO | WCN | $7.6M | 🔸 First-ever CEO purchase |
| 3 Co-Founders (Coppetti / Allemann / Bernhard) | Co-CEOs & Exec Officer | ONON | $6.6M | 🔥 First-ever founder buys, 2 days post-earnings |
| Noam Gottesman | Co-Chairman | NOMD | $6.6M | First visible buy by co-founder |
| Darren Richman | Officer | MRP | $6.4M | Second major buy, doubles position |
| Steven Cahillane | CEO | KHC | $5.0M | 🔸 First-ever open-market purchase |
| Ariel Emanuel + Mark Shapiro + CFO Schleimer | CEO / Officers | TKO | $4.5M | 🔥 Coordinated cluster since IPO |
| Bob Simpson | Director / 10% Owner | TXO | $3.9M | Co-founder buying, follows $9.5M on May 7 |
| Ernest Rady | Executive Chairman | AAT | $3.6M | Multi-year serial accumulator |
| Kenneth Courtis | Director | AMR | $2.8M | $40M accumulated over 9 months |
| 3 Insiders (CEO Rangan / CTO Shah / Dir. Norrington) | CEO / CTO / Director | HUBS | $2.6M | 🔥 Cluster buy after irrational 20% selloff |
| Manuel Perez De La Mesa | Director | POOL | $1.8M | Part of 4-director cluster |
| David Lorber | Chairman & CEO | PFX | $1.7M | Small-cap conviction |
| Steven Gunby + Paul Linton + CFO Nam | CEO / CSO / CFO | FCN | $2.1M | 🔥 Three-executive cluster at identical prices |
| Paul Gu | CEO | UPST | $1.4M | CEO averaging down ~30% below prior buy |
| Jared Isaacman | CEO / Founder (10% Owner) | FOUR | $15.9M | Multi-year consistent founder accumulator |
| Keith Meister / Corvex Mgmt | Director / 10% Owner | WGS | $13.8M | 🔥 Activist buying post-49% crash ($60M+ total) |
Cluster buys: multiple insiders, one company, one week
Cluster buying — when two or more separate insiders file Form 4 purchases at the same company within a rolling 7-day window — is widely considered the highest-quality insider signal category, since the probability of independently bad timing converges toward zero as the number of buyers rises.
On Holding AG (ONON) — three co-founders, first purchases ever
The standout event of the week. On May 14, all three On Holding co-founders — Caspar Coppetti (Co-CEO), David Allemann (Co-CEO), and Olivier Bernhard (Executive Officer) — each bought exactly 60,000 shares at $36.64, totaling $6.6M at near-identical prices. 3 The purchase came two days after On Holding reported record Q1 2026 results on May 12: net sales CHF 831.9M (+14.5%, or +26.4% in constant currency), net income CHF 103.3M (+82.2% year-over-year), gross margin 64.2%, and raised profit outlook. 4
What makes this signal unusual is the baseline: none of the three founders had filed a single open-market Form 4 purchase since ONON's IPO. Meanwhile, operational CEO Martin Hoffmann has been consistently selling 4,150 shares per week throughout 2026. Founders with zero prior purchase history choosing to buy immediately after a blowout quarter — and doing so simultaneously, not staggered — suggests a coordinated conviction signal rather than routine portfolio activity.
Post-purchase price as of May 17: ~$37.26 (+1.7% from the $36.64 purchase price). 3
HubSpot (HUBS) — CEO, CTO, and director buy the post-earnings dip
On May 7, HubSpot reported Q1 2026 results that beat on every headline metric: revenue $881M (+23%), non-GAAP EPS $2.72 vs. a $2.52 consensus estimate, and full-year guidance raised. 5 The stock then dropped roughly 20% after two Wall Street firms downgraded shares, citing a murkier growth outlook.
Four to five days into that decline, a three-person insider cluster bought: CTO Dharmesh Shah purchased 10,000 shares at $181.37 ($1.8M) on May 12; CEO Yamini Rangan bought 2,750 shares at $189.84 ($522K) on May 12; and Director Lorrie Norrington bought 1,313 shares at $190.42 ($250K) on May 11. 6 Combined: ~$2.6M from three insiders at prices $18–37 below where the stock traded pre-earnings.
Shah's 10,000 shares bring his total position to 1,322,400 shares. None of these three insiders have a long Form 4 purchase history on record, which limits the individual track record score — but the structural fact of CEO + CTO + Director all buying within 24 hours, after a selloff that appeared to be analyst-driven rather than fundamental, carries its own weight.
Post-purchase price as of May 17: ~$198.38 (+9.4% from Shah's $181.37). 6
TKO Group Holdings (TKO) — sustained executive cluster since IPO
On May 13, CEO Ariel Emanuel bought 10,805 shares at $185.09 ($2.0M), Mark Shapiro bought 10,807 shares at $185.05 ($2.0M), and CFO Andrew Schleimer bought 2,696 shares at $185.44 ($500K) — all at nearly identical prices on the same day, totaling ~$4.5M. 7 Q1 2026 results (reported around May 13) showed revenue $1.597B (+26%), adjusted EBITDA $549.8M (+32%), and a $1B share buyback authorization added. 8
The track record here is the cleanest of any cluster: Emanuel and Shapiro have been buying together since TKO's 2023 IPO at every price level from $79 to $185, including major tranches in January–February 2025 at $143–174. The May 13 purchase is the latest point in a multi-year, multi-executive accumulation pattern rather than a one-off event.
FTI Consulting (FCN) — CEO, Chief Strategy Officer, and CFO
FTI Consulting (FCN) is a global business advisory firm specializing in restructuring, litigation support, and economic consulting, with a market cap of approximately $4.3B. CEO Steven Gunby (10,000 shares at $144.17, $1.4M), Chief Strategy Officer Paul Linton (2,400 shares at $144.04, $346K), and CFO Eun Nam (2,000 shares at $144.59, $289K) all bought on May 13 at nearly identical prices. 9 Combined ~$2.1M. Gunby's prior purchase was October 24, 2025 at $151.12 ($1.1M) — slightly above current prices — so the current buy is not an average-up. Linton and Nam appear to be filing their first visible purchases. A CEO, CFO, and CSO buying at near-identical levels on the same day is a structurally strong signal regardless of the individual histories.
Pool Corp (POOL) — four directors, accelerating as prices fall
Director Manuel Perez De La Mesa has purchased POOL stock four times since late February: March 2 at $218 ($1.1M), March 13 at $205 ($1.0M), May 7 at $190 ($1.9M), and May 13 at $175.95 ($1.8M). 10 Each purchase came at a lower price than the last — accelerating position-building on weakness. In the same week (May 7–8), Directors David Whalen ($190.44), John Stokely ($193.07), and James Hope ($194.42) also filed purchases. Total cluster value across the week: ~$4.5M. Pool Corp (POOL) is the largest wholesale distributor of swimming pool supplies in the US, with a market cap of approximately $6.4B.
TXO Partners (TXO) — co-founder and director
TXO Partners (TXO) is an oil and gas master limited partnership (MLP) focused on the Permian and San Juan basins, with a market cap of approximately $722M. Bob Simpson, TXO's co-founder, Director, and 10% owner, purchased 750,000 shares at $12.61 ($9.5M) on May 7 and then 301,597 shares at $12.97 ($3.9M) on May 13. 11 Director William Adams also bought 10,000 shares at $12.41 ($124K) on May 8. The May 2025 cluster at TXO was even larger: Simpson, along with Directors Hutton, King, Massaro, and Kevil all bought at ~$15.00. Simpson continues buying at lower prices, now roughly 14% below that prior cluster price.
Notable solo buys
Sardar Biglari — Chairman & CEO, Biglari Holdings (BH), $13.4M
Biglari's May 12 purchase of 52,674 shares at $255.15 ($13.4M) is his largest single transaction of the past 12 months, and is consistent with a pattern stretching back to 2020: he buys more aggressively as the stock declines. 12 Prior purchases in early 2026 alone include Mar 3 at $331 ($379K), Mar 6 at $307 ($750K), Mar 9 at $301 ($1.0M), and Mar 13 at $302 ($849K). The current buy at $255 continues a step-down accumulation pattern — he bought at $300+ earlier this year and is now adding at prices not seen since 2021. Post-purchase holdings: 1,624,435 shares. Q1 2026 results (May 8) showed a net loss of $14.5M, an improvement from a $33.3M loss in Q1 2025, on revenue of $97.5M. 13 Current price ~$267.44 (+4.8% since purchase).
Ronald Mittelstaedt — President & CEO, Waste Connections (WCN), $7.6M
Mittelstaedt bought 50,000 shares at $152.24 on May 12 — this is his first-ever recorded Form 4 open-market purchase as CEO. 14 Prior WCN insider purchases on record were by directors in 2018 and 2022. The absence of a personal track record is noted, but a $7.6M debut purchase by a sitting CEO — 20 days after a solid Q1 report (revenue $2.37B, +6.4% year-over-year, EPS beat) — is a structurally notable event. 15 Post-purchase price: ~$156.61 (+2.9%).
Steven Cahillane — CEO, Kraft Heinz (KHC), $5.0M
Cahillane's purchase of 213,106 shares at $23.46 on May 12 is also a first — no prior Form 4 open-market purchases on record since he became CEO. 16 KHC has been in a multi-year decline from above $40, and currently trades near multi-year lows. Q1 2026 results (May 6) showed revenue of $6.05B (+0.8%), gross margin up 230 basis points to 36.7%, but organic sales of -0.4%, and Q2 revenue guided -3% to -5%. 17 Cahillane bought six days after earnings, fully aware of that near-term softness. Post-purchase price: ~$22.92 (-2.3%), still just below his cost basis.
Keith Meister / Corvex Management — Director, GeneDx (WGS), $13.8M this week ($60M+ total)
GeneDx (a genomic testing company) reported Q1 2026 on May 4: revenue $102.3M vs. a $112.5M consensus estimate, EPS -$0.28 vs. -$0.01 expected, and a guidance cut from $540–555M to $475–490M full-year revenue. 18 The stock fell 49% from ~$75 to ~$39. Meister, the activist investor running Corvex Management, bought $46.8M on May 7 (1,205,147 shares at $38.84), then continued into this window: May 13 (165,000 shares at $39.09, $6.4M), May 14 (140,000 shares at $39.39, $5.5M), and May 15 (46,273 shares at $38.91, $1.8M) — another $13.8M, for a cumulative position of roughly $60M+ built since May 7. 19
Meister's track record at WGS is one of sustained accumulation on weakness: he bought $8.6M in May 2025 at $56–60, then $13.5M in March 2026 at $79.40, and is now buying aggressively at $39 — roughly half the price of his March buy. His position has grown from approximately 3.4M shares in May 2025 to approximately 5.1M shares now. The pattern — buying more at lower prices, not capitulating — is consistent with activist conviction rather than averaging a mistake. The core risk is that the guidance cut represents a structural reimbursement rate problem, not a timing issue, and Meister's cost basis is well above current levels.
Jared Isaacman — CEO/Founder, Shift4 Payments (FOUR), $15.9M
Isaacman purchased 388,500 shares at $41.04 on May 11 ($15.9M) — his largest single transaction since an August 2025 buy at $82.81 ($16.3M). 20 He has been buying FOUR at every meaningful price level since 2022, with 2026 purchases also at $46.11 (Feb 26, $13.7M), $43.83 (Mar 2, $2.0M), and $45.75 (Mar 10, $2.0M). The May buy at $41 sits near the low end of his historical range ($31–$83). Q1 2026 results (May 7) were strong — gross revenue $1.12B (+32%), adjusted EBITDA $234M (+39%) — and the stock jumped 13% on the day. 21 Isaacman bought four days later, still at levels below pre-earnings. Note: Isaacman files as a 10% owner rather than a named executive officer — included here because he is the founder and CEO.
Noam Gottesman — Co-Chairman, Nomad Foods (NOMD), $6.6M
Gottesman (co-founder of Nomad Foods, the European frozen foods company behind Findus and Birds Eye) bought 700,000 shares at $9.47 on May 11 ($6.6M). 22 Director Ian Ashken added 100,000 shares at $9.13 ($913K) on May 13. 22 Nomad's Q1 2026 results (May 7) showed revenue -5.9% to €715.2M, organic revenue -5.3%, but an EPS beat; the company maintained its full-year 2026 guidance. 23 No prior Form 4 purchase filings for Gottesman are visible on OpenInsider — this appears to be his first recorded open-market buy. Co-founder buying for the first time after a period of revenue pressure, while maintaining guidance, is a signal worth noting. Post-purchase price: ~$9.80 (+3.5%).
Kenneth Courtis — Director, Alpha Metallurgical Resources (AMR), $2.8M
Courtis has been one of the most systematically aggressive director accumulators in this dataset over the past nine months: September 2025 ($148.55, $16.0M), December 2025 (three buys at $175–188, $10.7M), March 2026 (four buys at $176–191, $10.5M), and now May 2026 ($189.22 weighted average across nine lots, $2.8M). 24 Total accumulation: approximately $40M across roughly 9 months. AMR is a metallurgical coal producer (market cap ~$2.3B), a cyclical business where the stock has declined from ~$229 in December 2024 to ~$180 currently. Courtis's buying range spans from $148 to $191 — the current buy at $189 is near the top of that range, not an obvious dip purchase. Post-purchase price: ~$179.69 (-5.0%).
Ernest Rady — Executive Chairman, American Assets Trust (AAT), $3.6M
Rady bought 170,640 shares at $21.04 ($3.6M) on May 12 — continuing a multi-year accumulation pattern at this West Coast REIT. 25 Prior 2026 purchases include February 17 at $18.81 ($3.0M), February 20 ($3.1M across three filings), and February 25 at $19.78 ($213K). Rady has been buying AAT at prices ranging from $18 to $37 since at least 2022, never selling. AAT (market cap ~$1.3B) focuses on office, retail, multifamily, and mixed-use properties on the West Coast, and has been under pressure from commercial real estate headwinds. Post-purchase price: ~$20.77 (-1.3%).
Prem Watsa / Fairfax Financial — 10% Owner, Under Armour (UA), $5.9M
Watsa's May 12 purchase of 1,178,344 shares at $4.98 ($5.9M) is the most recent addition to an extraordinary accumulation campaign: since December 2025, Fairfax Financial has bought approximately 44.2M shares totaling ~$225M — at prices from $4.53 to $6.23. 26 Watsa is a well-known value investor (founder of Fairfax Financial Holdings, managing approximately $60B in assets). Under Armour's stock has declined from $25+ in 2021 to the current ~$5 area, and the May buy maintains that position without a clear near-term catalyst. The methodical pace — six tranches over five months — is consistent with a deep-value position-building strategy rather than a tactical trade. Note: Watsa files as a 10% owner, not a named executive. Included because of the scale of conviction and continued fresh accumulation.
Paul Gu — CEO, Upstart Holdings (UPST), $1.4M
Gu bought 50,000 shares at $27.50 on May 13 ($1.4M). 27 His prior Form 4 purchase was November 11, 2025 — 100,000 shares at $39.23 ($3.9M). The current buy is at roughly 30% below that prior cost. Director Dave Girouard also bought 170,240 shares at $29.37 ($5.0M) on May 7. Upstart (an AI-based lending platform) reported Q1 2026 results on May 5: revenue $308.2M (+44% year-over-year), beating estimates, with full-year guidance of $1.4B revenue reiterated. 28 The stock sold off post-earnings on a wider net loss of $6.6M. CEO and director buying into that weakness, at prices ~30% below the CEO's last disclosed buy, is an averaging-down signal. Post-purchase price: ~$29.51 (+7.3% from Gu's $27.50).
Signals with important caveats
First Citizens BancShares (FCNCA) — $10.3M headline, ~$206K net
Chairman and CEO Frank Holding Jr. filed a $10.3M purchase of 5,940 Class B Common shares at $1,726.82 on May 12. 29 The same Form 4 shows a simultaneous open-market sale of 5,346 Class A shares at $1,918.69 ($10.3M). Net buyer of 594 shares — approximately $206K in net economic exposure, not $10.3M. Both legs were open-market and filed through the "Frank B. Holding Jr. 2025 #1 GRAT" (a grantor retained annuity trust, a tax-planning vehicle that holds assets for a fixed term before passing to heirs). The most plausible interpretation is a Class A-to-Class B share conversion, likely motivated by the dual-class voting structure (Class B carries superior voting rights). Holding has 20+ prior Form 4 purchase filings since 2019, all small ($100K–$1M range). The headline number in raw screeners is misleading.
Cascade Investment / Bill Gates — 10% Owner, Republic Services (RSG), $100.5M
Cascade Investment, Bill Gates' investment vehicle, purchased 499,150 shares across May 11–13 at a weighted average of ~$201.40, totaling $100.5M. 30 Cascade holds ~110.3M RSG shares post-purchase and has been a holder for well over a decade. Prior major purchases: $117M in February 2022 at $116–117 per share; a small $1.0M add in August 2025 at $234.91. The current buy at $201 sits between those reference prices — above the 2022 entry, below the 2025 add. This is relevant data on Cascade's view of RSG's fair value, but it is not an executive officer signal — Gates has no operating role at Republic Services (a $64B waste management company). Categorized here rather than in Tier 1 because institutional 10% owner buying lacks the "personal compensation is on the line" dimension of executive conviction.
Biotech PIPE cluster — ARTV, ODTX, VRDN, PLSE, MOBI
Five biotech / medtech companies showed large Form 4 code-P filings this week that, on closer inspection, are likely private placements rather than open-market purchases: Artiva Biotherapeutics (ARTV, Ra Capital, $75M at $11.52), Odyssey Therapeutics (ODTX, TPG + Li Nan + SR One, $55M at $18.00 round price), Viridian Therapeutics (VRDN, Fairmount Funds, $20M at $17.00), Pulse Biosciences (PLSE, Robert Duggan, $26M at $19.69), and Mobia Medical (MOBI, Osage + Harrington, $18M at $15.00). 1 The round or near-round per-share prices and coordinated multiple-buyer entries at the same price are hallmarks of private placement rounds, which SEC Form 4 code P technically includes alongside true open-market exchange buys. These filings have not been excluded from the raw data — they are included in aggregate totals — but they should not be interpreted as executives buying in the open market at prevailing prices.
Methodology notes
10b5-1 plan status: Most transactions in this screen could not be independently verified for 10b5-1 automated trading plan status, as SEC EDGAR direct XML filings were inaccessible during this research period (HTTP 403). Only the FCNCA transaction was confirmed as non-10b5-1 via StockTitan's filing analysis. 29 A 10b5-1 plan trade is pre-scheduled in advance and does not reflect real-time discretionary conviction — readers tracking signals at companies where 10b5-1 use is common (e.g., large-cap tech executives) should verify the plan status before acting on any individual filing.
Code P covers two transaction types: SEC Form 4 transaction code "P" covers both open-market purchases on an exchange and private purchases from another person. Several transactions in the biotech cluster section above show characteristics consistent with PIPE rounds despite receiving code P. All transactions in the main analysis were verified via OpenInsider and cross-referenced with Finviz and Dataroma where available. 31 32
참고 출처
- 1OpenInsider: Top Insider Purchases of the Week
- 2Finviz: Latest Insider Trading (sorted by value)
- 3OpenInsider: ONON — On Holding AG Form 4 Screener
- 4On Holding Investor Relations: Q1 2026 Results
- 5Business Wire: HubSpot Q1 2026 Results
- 6OpenInsider: HUBS — HubSpot Inc Form 4 Screener
- 7OpenInsider: TKO — TKO Group Holdings Form 4 Screener
- 8Yahoo Sports: TKO Q1 2026 revenue
- 9OpenInsider: FCN — FTI Consulting Form 4 Screener
- 10OpenInsider: POOL — Pool Corp Form 4 Screener
- 11OpenInsider: TXO — TXO Partners LP Form 4 Screener
- 12OpenInsider: BH — Biglari Holdings Form 4 Screener
- 13Stock Titan: Biglari Holdings Q1 2026 Earnings
- 14OpenInsider: WCN — Waste Connections Form 4 Screener
- 15Waste Connections IR
- 16OpenInsider: KHC — Kraft Heinz Form 4 Screener
- 17Kraft Heinz Q1 2026 Press Release
- 18Stock Titan: GeneDx Q1 2026 Results
- 19OpenInsider: WGS — GeneDx Form 4 Screener
- 20OpenInsider: FOUR — Shift4 Payments Form 4 Screener
- 21Business Wire: Shift4 Q1 2026 Results
- 22OpenInsider: NOMD — Nomad Foods Form 4 Screener
- 23Nomad Foods Q1 2026 Earnings Release
- 24OpenInsider: AMR — Alpha Metallurgical Form 4 Screener
- 25OpenInsider: AAT — American Assets Trust Form 4 Screener
- 26OpenInsider: UA — Under Armour Form 4 Screener
- 27OpenInsider: UPST — Upstart Holdings Form 4 Screener
- 28Motley Fool: Upstart Q1 2026 Earnings Transcript
- 29StockTitan: FCNCA Form 4 Filing
- 30OpenInsider: RSG — Republic Services Form 4 Screener
- 31Finviz: Latest Insider Trading
- 32Dataroma: Real-Time Insider Data
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