Biodesix Stock Plunges 54%: Guidance Cut Halves the Shares

Biodesix (NASDAQ: BDSX) stock plunged more than 50% on Friday, November 6, 2026, after the lung diagnostics company cut its full-year revenue guidance following its third-quarter results. Shares fell about 54% to around $9.04 from a previous close of $19.84, touching an intraday low near $7.96, making Biodesix one of the day's biggest losers on US markets.

What happened

Biodesix reported third-quarter revenue of $24.0 million, up 10% from a year earlier, but below the roughly $27.49 million analysts had expected. The company reported a loss of $0.75 per share, meeting the consensus estimate, and a net loss of $8.0 million, which was 8% smaller than a year earlier.

The bigger shock was the outlook. Biodesix lowered its full-year 2026 revenue guidance to $101 million to $103 million. At the midpoint, that still represents about 15% growth over 2025, but it was well below what investors had been positioned for after a strong run in the shares earlier this year.

The numbers behind the fall

Underneath the headline miss, the core testing business was still growing. Diagnostic testing revenue rose 16% to $23.0 million, and test volumes climbed 24% to about 19,400 tests — the second-highest quarterly volume in the company's history. Gross margin held at 81%, the sixth consecutive quarter above 80%, and the adjusted EBITDA loss improved 16% to $3.9 million.

Two areas dragged on results. Development services revenue fell to $1.0 million from $1.9 million a year earlier as customers delayed project starts. And average revenue per test declined 6%, which management linked to a higher mix of Nodify CDT tests in the quarter.

Biodesix ended the quarter with $28.4 million in cash and cash equivalents, including $6.3 million in net proceeds from its at-the-market equity program.

Why it's blowing up

Management pointed to execution, not demand, as the main problem. The sales force averaged 101 representatives in the field during the quarter, below both the company's plan and its second-quarter average. Turnover was higher than anticipated, particularly in newer primary care territories, and hiring did not keep pace with attrition and planned expansion.

That shortfall mattered because new sales representatives are how Biodesix adds ordering physicians. Fewer reps in the field meant slower new-account growth, and stronger-than-expected primary care seasonality added to the pressure. Management said those three factors — sales capacity, seasonality and delayed development-services projects — explained the quarterly shortfall.

For investors, the combination was hard to ignore: a revenue miss, a guidance cut, and a cause — sales-force turnover — that cannot be fixed in one quarter.

What the company says comes next

Biodesix says commercial capacity is already recovering. The field team has risen to about 110 representatives, and the company plans to exit 2026 with about 115, then resume a hiring cadence of roughly six to eight representatives per quarter.

For the fourth quarter, development services revenue is expected to stay near $1 million, with several delayed projects now likely to move into 2027. Management said a prudent assumption for 2027 would place development services at about 7% to 8% of total revenue. The company continues to expect full-year gross margin of approximately 80% and further progress toward profitability.

Contracted development-services business also rose sequentially to $8.7 million, which management cited as evidence that biopharma demand remains intact despite slipped timing.

Key facts

• Stock move: down about 54% on Friday to around $9.04, from a $19.84 previous close
• Q3 revenue: $24.0 million, up 10% year over year, below about $27.49 million expected
• Diagnostic testing revenue: $23.0 million, up 16%, on test volume up 24% to about 19,400
• Net loss: $8.0 million; loss per share $0.75, in line with estimates
• New full-year 2026 guidance: $101 million to $103 million in revenue
• Cash: $28.4 million at quarter end

Sources: The Stock Observer, QuantiSnow summary of the Biodesix release, Motley Fool earnings call transcript, StockMarketWatch daily movers.

What's next

The next test is whether the rebuilt sales force shows up in ordering-physician growth and revenue in the fourth quarter and early 2027. Until investors see that capacity turn into sales, the guidance cut — not the 24% growth in test volumes — is likely to remain the story the market trades on. This article reports what happened and why the market reacted; it is not a recommendation to buy, sell or hold any security.

FAQ

Why did Biodesix stock fall so much today?

Biodesix cut its full-year 2026 revenue guidance to $101 million–$103 million after a third-quarter revenue miss, and blamed higher sales-force turnover, primary care seasonality and delayed projects.

What were Biodesix's Q3 2026 results?

Revenue was $24.0 million, up 10% year over year, with diagnostic testing revenue up 16% to $23.0 million, test volumes up 24%, gross margin of 81% and a net loss of $8.0 million.

Is Biodesix's testing demand falling?

Management said no — test volumes rose 24% to about 19,400, and it attributed the shortfall mainly to having fewer sales representatives in the field than planned.

What is Biodesix doing about the sales shortfall?

The field team has risen to about 110 representatives from a third-quarter average of 101, with a target of about 115 by year-end and a planned hiring pace of six to eight per quarter.