Total buying$00 buys
BLLN
BillionToOne, Inc.
NasdaqHealthcareServices-Medical Laboratories
Insider activity for last month from 09/19 to 10/19.
How these metrics are calculated
Counts use processed Form 4 rows. Purchase and sale metrics use codes P and S; totals remain unknown when any matching value is missing. Rows without a usable transaction date cannot be assigned to a rolling period and are excluded.
Total selling$7.43M32 sells
Net open-market−$7.43MBuying minus selling
Active insiders4Distinct reporting owners
Insider activity report
Calendar-month buckets within the selected date range
Latest filing: Oct 16, 2026
Open-market transaction mix · 32 transactions in the selected period
Code A includes awards, grants and other acquisitions; these are not open-market buys. A rolling period can include partial calendar months.
View exact monthly counts and disclosed values
| Month | Buys | Sells | Awards (A) | Buy value | Sell value | Net P/S value |
|---|---|---|---|---|---|---|
| Sep 2026 | 0 | 5 | 0 | $0 | $2.06M | -$2.06M |
| Oct 2026 | 0 | 27 | 0 | $0 | $5.37M | -$5.37M |
Distinct insiders active
Reporting-owner CIKs by month · peak Oct 2026 (4)Sep 2026Oct 2026
Largest insider activity
By absolute net disclosed value · current transaction page- AO-$2.9M
BLLN transaction history
Newest filings · 20 transactions per pageLatest insider transactions
Form 4 filings from last month.| Company | Insider | Activity | Disclosed value | Filed (ET) |
|---|---|---|---|---|
BLLNBillionToOne, Inc. | Atay OguzhanCHAIR | M · exercise10b5-1 detectedDerivative securitySEC filing ↗ | -$14.4kView disclosure → | |
BLLNBillionToOne, Inc. | Atay OguzhanCHAIR | M · exercise10b5-1 detectedDerivative securitySEC filing ↗ | -$8.91kView disclosure → | |
BLLNBillionToOne, Inc. | Atay OguzhanCHAIR | S · sale10b5-1 detectedSEC filing ↗ | -$261kView disclosure → | |
BLLNBillionToOne, Inc. | Atay OguzhanCHAIR | S · sale10b5-1 detectedSEC filing ↗ | -$13.6kView disclosure → | |
BLLNBillionToOne, Inc. | Atay OguzhanCHAIR | S · sale10b5-1 detectedSEC filing ↗ | -$99.7kView disclosure → | |
BLLNBillionToOne, Inc. | Atay OguzhanCHAIR | S · sale10b5-1 detectedSEC filing ↗ | -$128kView disclosure → | |
BLLNBillionToOne, Inc. | Atay OguzhanCHAIR | S · sale10b5-1 detectedSEC filing ↗ | -$185kView disclosure → | |
BLLNBillionToOne, Inc. | Atay OguzhanCHAIR | S · sale10b5-1 detectedSEC filing ↗ | -$88.5kView disclosure → | |
BLLNBillionToOne, Inc. | Atay OguzhanCHAIR | M · exercise10b5-1 detectedSEC filing ↗ | $14.4kView disclosure → | |
BLLNBillionToOne, Inc. | Atay OguzhanCHAIR | S · sale10b5-1 detectedSEC filing ↗ | -$9.90kView disclosure → | |
BLLNBillionToOne, Inc. | Atay OguzhanCHAIR | S · sale10b5-1 detectedSEC filing ↗ | -$303kView disclosure → | |
BLLNBillionToOne, Inc. | Atay OguzhanCHAIR | M · exercise10b5-1 detectedSEC filing ↗ | $8.91kView disclosure → | |
BLLNBillionToOne, Inc. | Atay OguzhanCHAIR | M · exercise10b5-1 detectedDerivative securitySEC filing ↗ | -$46.6kView disclosure → | |
BLLNBillionToOne, Inc. | Atay OguzhanCHAIR | S · sale10b5-1 detectedSEC filing ↗ | -$260kView disclosure → | |
BLLNBillionToOne, Inc. | Atay OguzhanCHAIR | S · sale10b5-1 detectedSEC filing ↗ | -$146kView disclosure → | |
BLLNBillionToOne, Inc. | Atay OguzhanCHAIR | S · sale10b5-1 detectedSEC filing ↗ | -$366kView disclosure → | |
BLLNBillionToOne, Inc. | Atay OguzhanCHAIR | S · sale10b5-1 detectedSEC filing ↗ | -$633kView disclosure → | |
BLLNBillionToOne, Inc. | Atay OguzhanCHAIR | S · sale10b5-1 detectedSEC filing ↗ | -$237kView disclosure → | |
BLLNBillionToOne, Inc. | Atay OguzhanCHAIR | S · sale10b5-1 detectedSEC filing ↗ | -$179kView disclosure → | |
BLLNBillionToOne, Inc. | Atay OguzhanCHAIR | M · exercise10b5-1 detectedSEC filing ↗ | $46.6kView disclosure → |
Filing-only signals
Deterministic matches in the selected period
Filing detail checks
Secondary metrics for the selected periodTransaction codes
By Form 4 transaction code in selected period48transactionstxns
- S · Open-market sells · dominant32 · 67%
- M · Option exercise16 · 33%
Activity by reported role
A joint filing can contribute to multiple rolesCHAIR24
CTO18
SLO4
SR2
Reported Holdings After
Separated by insider, security, and ownership type
Atay OguzhanClass A Common Stock · Direct
0Oct 15, 2026
Tsao DavidClass A Common Stock · Direct
1,000Oct 05, 2026
Ten Bosch John RoderickClass A Common Stock · Direct
19,385Oct 05, 2026
Atay OguzhanStock Option (right to buy) · Direct
468,629Oct 15, 2026
Tsao DavidStock Option (right to buy) · Direct
536,667Oct 05, 2026
Atay OguzhanClass A Common Stock · Indirect · By spouse
149,168Oct 14, 2026
Lynch Thomas P.Class A Common Stock · Direct
8,700Oct 08, 2026
Lynch Thomas P.Stock Option (right to buy) · Direct
40,974Oct 08, 2026
These are reported post-transaction holdings, not company-wide ownership percentages. Securities, indirect vehicles, and amendments are kept separate.
Filing activity heatmap
Current transaction page only · each cell is a filing date · buys green, sells redSep 19 → Oct 19
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BillionToOne, Inc. Insider Activity FAQ
SEC Form 4 contextWho recently reported transactions at BillionToOne, Inc.?
Atay Oguzhan, Lynch Thomas P., ten Bosch John Roderick, Tsao David.
When was the latest reported open-market purchase?
No code-P purchase is available for this period.
When was the latest reported open-market sale?
Atay Oguzhan reported a sale on Oct 15, 2026 valued at $13.6k. Read the SEC filing.
What is the recent purchase and sale balance?
Net open-market selling in the selected period was $7,439,394.13. Sales can occur for many non-investment reasons.
Where can I see the original SEC filing?
Every transaction row and latest-activity fact links to its original SEC filing.
What do these Form 4 transaction codes mean?
P and S generally describe open-market or private purchases and sales. A, D, F, M, X, G, J, and V describe awards, issuer dispositions, tax withholding, exercises, gifts, other transactions, and voluntary early reports; review each filing and its footnotes for context.