BillionToOne BLLN Insider Ownership

Updated Oct 10, 2026

Over the past year, BLLN insiders bought $3.18 million of stock (52.97K shares) and sold $48.43 million (425.73K shares) on the open market.

• Behind BillionToOne's open-market trades in the past 12 months were 6 insiders buying and 6 insiders selling.
• Among BillionToOne's insiders, the largest open-market purchases in the past 12 months were by Thomas S. Bremner (Director), totaling $2.5 million (41.67K shares), most recently on November 7, 2025.
• Meanwhile, the largest open-market sales of BLLN in the past 12 months were by Oguzhan Atay (Chairman and CEO), totaling $22.95 million (191.87K shares), most recently on September 28, 2026.
• BillionToOne's latest insider trade on the open market was a sale of 20K shares for $2.16 million by David Tsao (Chief Technology Officer) on October 5, 2026.
• Apart from open-market trades, BLLN insiders received 16.25K shares in stock awards, acquired 19.15Mn shares through option exercises and conversions and gave away 53.5K shares as gifts in the past 12 months.
• According to Business Quant data, insiders at BillionToOne reported 12.99Mn shares in total in their latest Form 4 filings, or 27.74% of the 46.83Mn shares outstanding; that total is down 0.65% from 13.08Mn shares at the end of Q2 2026.
• BillionToOne insiders hold 4.9Mn shares directly (37.72% of their total) and 8.09Mn shares (62.28%) indirectly, through entities such as trusts and partnerships.
• Holdings in BillionToOne stock are reported by 13 insiders, the officers, directors and 10% owners who have filed a Form 4 in the past two years.
• BillionToOne's three biggest insider holders are Krishna Kittu Kolluri (Director, 2.89Mn shares), Humming Bird Ventures Management NV (10% owner, 2.58Mn shares) and Oguzhan Atay (Chairman and CEO, 2.35Mn shares), based on their latest Form 4 filings.
• Krishna Kittu Kolluri holds 22.24% of the combined insider position in BillionToOne.
• Institutional investors owned 32.63% of BLLN shares as of Q2 2026, per their 13F filings.
• Over the past 12 months, 15 insiders reported transactions in BillionToOne stock in 61 Form 4 filings.
• The insider holdings and trades above for BillionToOne reflect Form 4 filings through October 7, 2026.