Biggest insider buys, week of Sep 28–Oct 4, 2026: Kodiak Sciences (KOD) leads with $157M
Insiders reported 407 purchases of common stock across 110 companies in SEC Form 4 filings. These are the five U.S. companies with the most insider buying by dollar value.
Industry: Biological Products, (No Diagnostic Substances). SEC ↗
One insider bought 1,941,755 shares in 82 transactions at an average of $80.85 a share.
- BAKER BROS. ADVISORS LP; 667, L.P.; Baker Bros. Advisors (GP) LLC; Baker Brothers Life Sciences LP; BAKER FELIX; BAKER JULIAN, Director: bought 278,978 shares at $72.39 ($20.19M) on Sep 28, 2026. Filed Sep 30, 2026. View Form 4 on SEC.gov ↗
- BAKER BROS. ADVISORS LP; 667, L.P.; Baker Bros. Advisors (GP) LLC; Baker Brothers Life Sciences LP; BAKER FELIX; BAKER JULIAN, Director: bought 196,608 shares at $89.86 ($17.67M) on Sep 28, 2026. Filed Sep 30, 2026. View Form 4 on SEC.gov ↗
- BAKER BROS. ADVISORS LP; 667, L.P.; Baker Bros. Advisors (GP) LLC; Baker Brothers Life Sciences LP; BAKER FELIX; BAKER JULIAN, Director: bought 123,888 shares at $83.95 ($10.4M) on Sep 28, 2026. Filed Sep 30, 2026. View Form 4 on SEC.gov ↗
All insider trades in KOD →79 smaller transactions not listedGroup 1 Automotive, Inc. is an international Fortune 300 automotive retailer with automotive dealerships and collision centers in the United States and the United Kingdom. Wikipedia (CC BY-SA 4.0) ↗
One insider bought 400,000 shares in 42 transactions at an average of $244.51 a share.
- Conifer Management, L.L.C., 10% owner: bought 42,495 shares at $247.96 ($10.54M) on Sep 24, 2026. Filed Sep 28, 2026. View Form 4 on SEC.gov ↗
- Conifer Management, L.L.C., 10% owner: bought 34,593 shares at $243.23 ($8.41M) on Sep 28, 2026. Filed Sep 30, 2026. View Form 4 on SEC.gov ↗
- Conifer Management, L.L.C., 10% owner: bought 34,446 shares at $242.27 ($8.35M) on Sep 28, 2026. Filed Sep 30, 2026. View Form 4 on SEC.gov ↗
All insider trades in GPI →39 smaller transactions not listedCorebridge Financial, Inc. is an American financial services company. Wikipedia (CC BY-SA 4.0) ↗
One insider bought 1,808,533 shares in 6 transactions at an average of $33.99 a share.
- NIPPON LIFE INSURANCE CO, 10% owner: bought 736,814 shares at $34.10 ($25.12M) on Sep 28, 2026 under a 10b5-1 plan. Filed Sep 30, 2026. View Form 4 on SEC.gov ↗
- NIPPON LIFE INSURANCE CO, 10% owner: bought 348,215 shares at $33.65 ($11.72M) on Sep 30, 2026 under a 10b5-1 plan. Filed Oct 2, 2026. View Form 4 on SEC.gov ↗
- NIPPON LIFE INSURANCE CO, 10% owner: bought 258,878 shares at $33.85 ($8.76M) on Sep 24, 2026 under a 10b5-1 plan. Filed Sep 28, 2026. View Form 4 on SEC.gov ↗
All insider trades in CRBG →3 smaller transactions not listedLennar Corporation (LEN), commonly known as Lennar, is an American home construction company based in Miami-Dade County, Florida. Wikipedia (CC BY-SA 4.0) ↗
One insider bought 660,410 shares in 5 transactions at an average of $81.59 a share.
- BERKSHIRE HATHAWAY INC; BUFFETT WARREN E, 10% owner: bought 638,813 shares at $81.59 ($52.12M) on Sep 30, 2026. Filed Sep 30, 2026. View Form 4 on SEC.gov ↗
- BERKSHIRE HATHAWAY INC; BUFFETT WARREN E, 10% owner: bought 12,289 shares at $81.95 ($1.01M) on Sep 29, 2026. Filed Sep 30, 2026. View Form 4 on SEC.gov ↗
- BERKSHIRE HATHAWAY INC; BUFFETT WARREN E, 10% owner: bought 5,200 shares at $81.96 ($426.19K) on Sep 28, 2026. Filed Sep 30, 2026. View Form 4 on SEC.gov ↗
All insider trades in LEN →2 smaller transactions not listedIndustry: Pharmaceutical Preparations. SEC ↗
2 insiders bought 2,550,000 shares in 6 transactions at an average of $17.00 a share.
- George Simeon, Director: bought 592,593 shares at $17.00 ($10.07M) on Sep 28, 2026. Filed Sep 29, 2026. View Form 4 on SEC.gov ↗
- George Simeon, Director: bought 592,593 shares at $17.00 ($10.07M) on Sep 28, 2026. Filed Sep 29, 2026. View Form 4 on SEC.gov ↗
- ORBIMED ADVISORS LLC; OrbiMed Capital GP VII LLC; OrbiMed Israel GP II, L.P.; OrbiMed Advisors Israel II Ltd; OrbiMed Genesis GP LLC, Director: bought 588,235 shares at $17.00 ($10M) on Sep 28, 2026. Filed Sep 30, 2026. View Form 4 on SEC.gov ↗
All insider trades in ADRX →3 smaller transactions not listed
How this report is made
This report is compiled automatically from SEC Form 4 filings received during the week shown. Companies are ranked by the total dollar value of insider purchases (transaction code P, open-market or private purchase). “Insiders” include officers, directors and owners of more than 10% of a company, which can be investment funds. Only common stock is counted: preferred shares, units and derivatives are left out, as are filings that fail our data checks. When a fund and the insider who controls it both report the same trade, it is counted once. Only U.S.-based companies are ranked, because insiders of foreign companies sometimes report prices in their local currency.
Every figure comes from the original filing, which is linked in each entry; the filing is the authoritative record. This is information, not investment advice. See the methodology, disclaimer and corrections policy.