Wednesday, October 28, 2026
Data from SEC filings, checked daily
Public filings, plainly told
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BLLN Insider Trading and Fund Holdings (BillionToOne, Inc.) · https://wallstpal.com/stock/blln/ · saved 2026-10-28

About this page

Insider trades reported on SEC Form 4: when the people who run a company buy or sell its shares with their own money.

How to read it

Form 4
The form a company insider (officer, director or owner of more than 10%) must file with the SEC within two business days of buying or selling the company's shares.
Buy (P) and Sell (S)
Open-market purchases and sales. Gifts, option exercises and automatic tax withholding are left out because they say little about what the insider thinks.
Value
Shares times price, as reported on the filing.
10b5-1
A trade made under a plan set up in advance. Planned sales are common and usually say less than an unplanned purchase.
Late filing
A Form 4 filed more than two business days after the trade.
Vs. S&P 500
How the stock did after the trade minus how the overall market did in the same weeks.

A real example

In January 2016, when bank stocks were falling, JPMorgan Chase CEO Jamie Dimon bought 500,000 JPMorgan shares with his own money, worth about $26 million. His Form 4 made the purchase public within days, and investors read it as a strong sign of confidence.

Explain it like I'm 13

If the coach of a team bets his own allowance that his team will win, that tells you something. A Form 4 is the note a company boss must hand in whenever he buys or sells his own company's shares, so everyone can see it.

Data from public SEC filings and congressional reports. Information, not investment advice. Check every number against the filing linked on the page.

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StockCIK 2070849

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

In the past 12 months, BillionToOne, Inc. insiders reported no open-market purchases and 38 sales worth $45.4M; 38 of the sales were reported as made under a 10b5-1 trading plan.

0Insider buys, 12 months
$0Bought by insiders, 12 months
$45.4MSold by insiders, 12 months
1Tracked funds holding

Timeline: news and trades

Company filings (8-K), insider trades, notices of planned sales (Form 144), Congress trades 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. Aug 10, 2026Insider saleCTO David Tsao sold $928,600 under a 10b5-1 plan
  40. Aug 10, 2026Insider saleSVP Bosch John Roderick Ten sold $131,583 under a 10b5-1 plan

Showing the latest 40 of 56 events.

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 38 BLLN insider trades →

Insiders who traded in the past year

InsiderRoleBuysBoughtSellsSoldLatest
Oguzhan AtayCEO0$015$22.1MOct 16, 2026
David TsaoCTO0$07$11.0MOct 7, 2026
Bosch John Roderick TenSVP0$09$2.02MOct 7, 2026
Thomas P. LynchSee Remarks0$02$5.87MSep 21, 2026
Shan Riku SakakibaraChief Product Officer0$03$2.44MAug 4, 2026
Nancy Joann JohnsonSee Remarks0$02$1.92MJul 20, 2026
Filing quality

A All 38 insider trades reported on time. How it is graded

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 →