BillionToOne should keep taking share from Natera because its products' efficacy is far ahead, and it has a good chance of becoming a $100B-plus company. Few companies grow this fast with such an intriguing business model while already profitable. A share price above $100 does not make it expensive, since it has fewer than 50M shares outstanding and price per share says nothing about size or upside. x.com  x.com  x.com 

Natera is the best short in diagnostics because its valuation demands accelerating KPIs that are likely to slow. Signatera is great, but growth should decelerate, while the legacy women's health business is highly penetrated and facing competition from BillionToOne. Opex should rise next year more than the buy side expects, and the stock is crowded with tourists. Even 25% sales growth for a decade with 25% EBITDA margins yields only about $250 a share on a DCF. x.com  x.com  x.com  x.com  x.com 

Biodesix's technology could become strategically important to multiple acquirers as more multicancer screening finds lung nodules needing risk stratification. Its shares trade at 2.63x gross profit, and growth should reach 23-24% when it reports on November 5. Chief Scientific Officer Gary Pestano's November 11 MRD talk is another point to watch. Permanent capital loss remains possible. x.com 

Guardant Health's Shield has the edge over Freenome in colorectal screening. The data are the same, but Guardant gives patients a free option to screen for other cancers and has better coverage, making it more seamless. Freenome was supposed to differentiate on advanced adenoma detection, but its results were mediocre. x.com 

Tempus AI's diagnostics-to-data-to-AI flywheel makes its roughly 7.2x forward sales interesting, about half Natera's and Guardant's 16x, though both grow faster. Q2 revenue rose 22% to $382.5M, Data Licensing & Modeling grew 36%, and 2026 guidance is about $1.6B of revenue and $65M of adjusted EBITDA. As a ~25% growth diagnostics company, ~7x may be reasonable; if growth reaccelerates toward 30%+, Data + Applications grows much larger and margins expand, the valuation could look very different. … Show more

Personalis is following Natera's playbook, moving its revenue inflection from theoretical to measurable. In 2026 it is deliberately buying share over margin, guiding 43K-45K clinical tests but only $10-11M of clinical revenue. Four Medicare coverages across breast cancer, lung cancer and immunotherapy monitoring each open multiyear surveillance. If conversion tracks Natera, revenue could reach $175-220M in 2027 and $320-400M in 2028. Tempus agreed to acquire it at $16.25 per share. x.com 

Natera's business strengthened with a hat trick of regulatory milestones in a single quarter, while gross margins run at 64-66%. x.com 

Guardant Health's Q2 drove its rally: revenue rose 44% to $335 million, comfortably beating expectations, and it raised its year-end revenue target to $1.35 billion. Technically, all moving averages are stacked and the stock has rested between $145 and $175 since early July; a high-volume break above $170 would leave clear room upward. x.com 

Guardant Health still looks overvalued because its Shield screening economics are not proven at scale. Management's own 2028 guidance of about $2.2 billion revenue has not been raised, and Shield's unit economics remain weak, with high COGS and dilution at current volumes. Even on @somebakedziti's upside case of $2.8 billion revenue and a 25x multiple, the 2028 price is in the mid-$90s, worth about $65-78 today. Better reimbursement does not change current unit economics or valuation. x.com 

GeneDx's proposed Medicare cuts may have a much smaller direct impact than its selloff implies. Craig-Hallum estimates a $5.6 million annual hit, about 1% of exome and genome revenue. Q2 testing volume grew 32%, though revenue per test is declining; the proprietary rare-disease database and potential for AI-driven interpretation remain compelling. At $65, risk/reward might be attractive again, but reimbursement, profitability and execution remain risks. November 3 earnings should clarify. x.com