BLLN BillionToOne, Inc.

NASDAQ
$123.08

BillionToOne, Inc. (BLLN) Insider Activity

What the officers, directors and large holders did with their own shares. Only open-market purchases and sales count toward the totals — grants, option exercises and shares withheld for tax are compensation mechanics, not decisions, and they're listed separately below.

Insider signal Bearish Selling ran elevated versus BLLN's own trailing one-year pace, with 100% of sale value under a prearranged plan.
Cluster activity 0 buyers in the last 30 days 0 buyers in the last 90 days 6 sellers in the last 90 days
Insiders buying
0
0 transactions
Insiders selling
6
116 transactions
Purchases
$0
0 shares
Sales
$34.9M
295,565 shares
Net activity
-$34.9M
purchases less sales

How much of that selling was preplanned? 100% planned / 0% discretionary

10b5-1 plan sales $34.9M 116 transactions · 295,565 shares
Discretionary sales $0 0 transactions · 0 shares

Largest single sale: $2.3M.

Where they traded

Buy Sell Dot area is proportional to transaction value.

Last open-market purchase: November 7, 2025 , by Lynch Thomas P. .

Recent open-market activity

Date Insider Role Action Shares Price Value Held after
ten Bosch John Roderick SVP of Laboratory Operations Sell 10b5-1 1,416 $106.61 $151.0K 23,635 −5.7% of holding
Lynch Thomas P. 4 fills See Remarks Sell 10b5-1 35,112 $110.33 $3.9M 16,428 −68.1% of holding
Atay Oguzhan 10 fills Chairman and CEO Sell 10b5-1 30,331 $99.91 $3.0M 159,834 −15.9% of holding
Tsao David 2 fills Chief Technology Officer Sell 10b5-1 20,000 $98.77 $2.0M 11,000 −64.5% of holding
ten Bosch John Roderick SVP of Laboratory Operations Sell 10b5-1 1,416 $97.54 $138.1K 25,051 −5.4% of holding
Lynch Thomas P. 13 fills See Remarks Sell 10b5-1 20,000 $99.99 $2.0M 20,662 −49.2% of holding
Tsao David Chief Technology Officer Sell 10b5-1 10,000 $100.00 $1.0M 1,000 −90.9% of holding
ten Bosch John Roderick SVP of Laboratory Operations Sell 10b5-1 1,417 $100.00 $141.7K 26,467 −5.1% of holding
Tsao David Chief Technology Officer Sell 10b5-1 10,000 $92.86 $928.6K 1,000 −90.9% of holding
ten Bosch John Roderick SVP of Laboratory Operations Sell 10b5-1 1,417 $92.86 $131.6K 27,884 −4.8% of holding
Atay Oguzhan Chairman and CEO Sell 10b5-1 15,539 $150.03 $2.3M None left
Atay Oguzhan 23 fills Chairman and CEO Sell 10b5-1 45,000 $137.07 $6.2M 168,750 −21.1% of holding
Sakakibara Shan Riku Chief Product Officer Sell 10b5-1 4,000 $140.21 $560.8K 200,000 −2% of holding
Johnson Nancy JoAnn 4 fills See Remarks Sell 10b5-1 14,199 $128.29 $1.8M 18,966 −42.8% of holding
Tsao David 10 fills Chief Technology Officer Sell 10b5-1 20,000 $124.88 $2.5M 19,898 −50.1% of holding
ten Bosch John Roderick 3 fills SVP of Laboratory Operations Sell 10b5-1 4,251 $125.46 $533.3K 32,135 −11.7% of holding
Atay Oguzhan 4 fills Chairman and CEO Sell 10b5-1 12,500 $126.10 $1.6M 5,011 −71.4% of holding
Sakakibara Shan Riku 5 fills Chief Product Officer Sell 10b5-1 8,000 $125.00 $1.0M 208,000 −3.7% of holding
Atay Oguzhan 28 fills Chairman and CEO Sell 10b5-1 38,750 $122.05 $4.7M 186,466 −17.2% of holding
Johnson Nancy JoAnn See Remarks Sell 10b5-1 801 $124.91 $100.1K 21,099 −3.7% of holding
ten Bosch John Roderick SVP of Laboratory Operations Sell 10b5-1 1,416 $120.00 $169.9K 33,552 −4% of holding

Form 4s are due within two business days of a transaction, so this is close to real time — unlike the quarterly 13F data on the Institutional tab. A single large sale often reflects a prearranged 10b5-1 plan rather than a fresh view, so read a pattern of sales rather than any one of them.