Wednesday, October 28, 2026
Data from SEC filings, checked daily
Public filings, plainly told
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StockCIK 2070849

BillionToOne, Inc. (BLLN): Insider Trades and Fund Holdings

In the past 12 months, BillionToOne, Inc. insiders reported 0 open-market purchases worth $0 and 20 sales worth $19.6M; 20 of the sales were reported as made under a 10b5-1 trading plan.

0Insider buys, 12 months
$0Bought by insiders, 12 months
$19.6MSold by insiders, 12 months
1Tracked funds holding

Timeline: news and trades

Company filings (8-K), insider trades, notices of planned sales (Form 144) and fund moves in the past year, newest first.

  1. Oct 15, 2026Insider saleCEO Oguzhan Atay sold $516,188 under a 10b5-1 plan
  2. Oct 15, 2026Planned saleAtay Oguzhan (officer, director) filed notice to sell about $516,189 around Oct 15, 2026
  3. Oct 14, 2026Insider saleCEO Oguzhan Atay sold $574,386 under a 10b5-1 plan
  4. Oct 14, 2026Planned saleAtay Oguzhan (officer, director) filed notice to sell about $313,020 around Oct 14, 2026
  5. Oct 14, 2026Planned saleAtay Oguzhan (member of immediate family of any of the foregoing) filed notice to sell about $261,366 around Oct 14, 2026
  6. Oct 13, 2026Planned saleAtay Oguzhan (officer, director) filed notice to sell about $1.6 million around Oct 12, 2026
  7. Oct 13, 2026Planned saleAtay Oguzhan (member of immediate family of any of the foregoing) filed notice to sell about $260,326 around Oct 12, 2026
  8. Oct 12, 2026Insider saleCEO Oguzhan Atay sold $1.8 million under a 10b5-1 plan
  9. Oct 5, 2026Insider saleCTO David Tsao sold $2.2 million under a 10b5-1 plan
  10. Oct 5, 2026Insider saleSVP Bosch John Roderick Ten sold $297,996 under a 10b5-1 plan
  11. Oct 5, 2026Planned saleTsao David (officer, director) filed notice to sell about $2.2 million around Oct 5, 2026
  12. Oct 5, 2026Planned saleten Bosch John Roderick (officer) filed notice to sell about $297,995 around Oct 5, 2026
  13. Oct 5, 2026Planned saleTsao David (officer, director) filed notice to sell about $184,013 around Oct 5, 2026
  14. Sep 28, 2026Insider saleCEO Oguzhan Atay sold $1.3 million under a 10b5-1 plan
  15. Sep 28, 2026Planned saleAtay Oguzhan (officer, director) filed notice to sell about $1 million around Sep 28, 2026
  16. Sep 28, 2026Planned saleAtay Oguzhan (member of immediate family of any of the foregoing) filed notice to sell about $321,626 around Sep 28, 2026
  17. Sep 24, 2026Insider saleCTO David Tsao sold $416,625 under a 10b5-1 plan
  18. Sep 24, 2026Insider saleSVP Bosch John Roderick Ten sold $169,920 under a 10b5-1 plan
  19. Sep 24, 2026Planned saleTsao David (officer, director) filed notice to sell about $416,625 around Sep 24, 2026
  20. Sep 24, 2026Planned saleten Bosch John Roderick (officer) filed notice to sell about $169,920 around Sep 24, 2026
  21. Sep 21, 2026Insider saleSVP Bosch John Roderick Ten sold $150,960 under a 10b5-1 plan
  22. Sep 21, 2026Planned saleten Bosch John Roderick (officer) filed notice to sell about $150,960 around Sep 21, 2026
  23. Sep 17, 2026Insider saleSee Remarks Thomas P. Lynch sold $3.9 million under a 10b5-1 plan
  24. Sep 17, 2026Planned saleLynch Thomas P. (officer) filed notice to sell about $3.9 million around Sep 17, 2026
  25. Sep 14, 2026Insider saleCEO Oguzhan Atay sold $3 million under a 10b5-1 plan
  26. Sep 14, 2026Planned saleAtay Oguzhan (officer, director) filed notice to sell about $2.5 million around Sep 14, 2026
  27. Sep 14, 2026Planned saleAtay Oguzhan (member of immediate family of any of the foregoing) filed notice to sell about $522,536 around Sep 14, 2026
  28. Sep 9, 2026Insider saleCTO David Tsao sold $2 million under a 10b5-1 plan
  29. Sep 9, 2026Insider saleSVP Bosch John Roderick Ten sold $138,117 under a 10b5-1 plan
  30. Sep 9, 2026Planned saleTsao David (officer, director) filed notice to sell about $2 million around Sep 9, 2026
  31. Sep 9, 2026Planned saleTsao David (officer, director) filed notice to sell about $170,695 around Sep 9, 2026
  32. Sep 9, 2026Planned saleten Bosch John Roderick (officer) filed notice to sell about $138,117 around Sep 9, 2026
  33. Sep 8, 2026Insider saleSee Remarks Thomas P. Lynch sold $2 million under a 10b5-1 plan
  34. Sep 8, 2026Planned saleLynch Thomas P. (officer) filed notice to sell about $2 million around Sep 8, 2026
  35. Aug 25, 2026Insider saleCTO David Tsao sold $1 million under a 10b5-1 plan
  36. Aug 25, 2026Insider saleSVP Bosch John Roderick Ten sold $141,700 under a 10b5-1 plan
  37. Aug 25, 2026Planned saleTsao David (officer, director) filed notice to sell about $1 million around Aug 25, 2026
  38. Aug 25, 2026Planned saleten Bosch John Roderick (officer) filed notice to sell about $141,700 around Aug 25, 2026
  39. Jun 30, 2026FundSoros Fund Management sold out in Q2 2026 (13F filed Aug 14, 2026)
  40. Jun 30, 2026FundRenaissance Technologies added 89% in Q2 2026 (13F filed Aug 13, 2026)

Recent insider trades

Open-market purchases (code P) and sales (code S) from Form 4. Grants, option exercises and gifts are not shown. Latest filing: Oct 16, 2026.

Recent BLLN insider trades
FiledTradedInsiderRoleTypeSharesPrice ($)ValueHoldingFiling
Oct 16Oct 15Oguzhan AtayCEOCEO▼ SELL10b5-15,150100.23$516KAll soldForm 4 ↗
Oct 16Oct 14Oguzhan AtayCEOCEO▼ SELL10b5-13,18398.34$313KAll soldForm 4 ↗
Oct 16Oct 14Oguzhan AtayCEOCEO (ind.)▼ SELL10b5-12,66798.00$261K−1.8%Form 4 ↗
Oct 14Oct 12Oguzhan AtayCEOCEO▼ SELL10b5-116,66793.79$1.56MAll soldForm 4 ↗
Oct 14Oct 12Oguzhan AtayCEOCEO (ind.)▼ SELL10b5-12,66797.61$260K−1.7%Form 4 ↗
Oct 7Oct 5David TsaoCTOCTO▼ SELL10b5-120,000108.15$2.16M−72%Form 4 ↗
Oct 7Oct 5Bosch John Roderick TenSVPSVP▼ SELL10b5-12,834105.15$298K−13%Form 4 ↗
Sep 30Sep 28Oguzhan AtayCEOCEO▼ SELL10b5-18,333120.64$1.01MAll soldForm 4 ↗
Sep 30Sep 28Oguzhan AtayCEOCEO (ind.)▼ SELL10b5-12,666120.64$322K−1.7%Form 4 ↗
Sep 28Sep 24David TsaoCTOCTO▼ SELL10b5-13,333125.00$417K−77%Form 4 ↗
Source: SEC Form 4 filings, retrieved Oct 28, 2026. How we read filings
All 20 BLLN insider trades →

Insiders who traded in the past year

InsiderRoleBuysBoughtSellsSoldLatest
Oguzhan AtayCEO0$09$7.27MOct 16, 2026
David TsaoCTO0$04$5.55MOct 7, 2026
Bosch John Roderick TenSVP0$05$899KOct 7, 2026
Thomas P. LynchSee Remarks0$02$5.87MSep 21, 2026

Tracked funds that report BLLN

From each fund's latest 13F. Holdings are as of quarter end and are filed up to 45 days later.

FundQuarterSharesValue% of portfolioChange
Renaissance TechnologiesQ2 202696,600$11.6M0.02%▲ +88.5%
Soros Fund ManagementQ2 20260$00.00%▼ Sold out
Source: SEC Form 13F-HR filings, retrieved Oct 28, 2026. How we read filings

Reading these numbers

Insiders sell for many reasons: taxes, diversification, a house. Purchases with their own money are rarer and are usually read as more informative. A Form 4 is due within two business days of the trade. How to read a Form 4 →