Company: BLLN
Filing Date: 2025-12-10
Form Type: 10-Q
Source: 0001628280-25-056321
Chunk: 229

Company: BillionToOne, Inc.
Filing Date: 2025-12-10
Form: 10-Q
Item: Part I, Item 1
Chunk 229
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 of the improvement in gross margin for the nine months ended September 30, 2025.

For the nine months ended September 30, 2025, our cost of goods sold consisted of 56% of variable costs and 44% of fixed costs and for the nine months ended September 30, 2024 our cost of goods sold consisted of 55% of variable costs and 45% of fixed costs. The increase in variable costs during the period is attributable primarily to an increase in test volume from prenatal testing, partially offset by efficiencies gained in in our lab from the increased test volume in both prenatal and oncology testing.

Operating expenses

Research and development expenses

Research and development expenses increased $9.5 million, or 37%, for the nine months ended September 30, 2025 compared to the nine months ended September 30, 2024. The increase was primarily due to a $7.3 million increase in personnel costs which includes $0.8 million in stock-based compensation expense and a $2.7 million increase in materials, equipment expenses and overhead allocations. These amounts were partially offset by a $0.5 million decrease in clinical studies expense. The increase in research and development expenses was primarily driven by an increase in average research and development headcount of 31 employees during the periods presented to support our product development and innovation efforts.

Selling, general and administrative expenses

Selling, general and administrative expenses increased $34.0 million, or 52%, for the nine months ended September 30, 2025 compared to the nine months ended September 30, 2024. The increase was primarily due to a $26.7 million increase in salaries, commissions and related expenditure which includes $2.3 million in stock-based compensation expense, a $4.0 million increase in facilities and other costs, and a $3.1 million increase in professional and consulting fees. The increase in selling, general and administrative expenses was driven by an increase in average selling, general and administrative headcount of 101 employees during the periods presented to support our sales, marketing and other corporate strategies.

Interest income

Interest income increased by $0.3 million, or 8%, for the nine months ended September 30, 2025 compared to the nine months ended September 30, 2024. The increase was due to higher average balances of cash and cash equivalents.

38

Interest expense

Interest expense decreased $2.2 million, or 96%, for the nine months ended