For all the noise in genomics, few arcs are as neat as this one. In January 2022, Sema4, a Mount Sinai spinout fresh from a SPAC merger that brought in $500 million in cash, agreed to buy GeneDx from OPKO Health: $150 million upfront in cash plus 80 million shares, about $473 million, with another $150 million in milestones taking the total to roughly $623 million. Three years later, a short seller was alleging the combined company, now named GeneDx, was inflating revenue by about a quarter through improper billing. The salient point for investors: the same acquisition that founded the growth story is now Exhibit A in the case against it.
The 2022 deal was sold as data science. Sema4’s platform applied artificial intelligence to 12 million de-identified patient records; GeneDx added sequencing services and a database of clinical exomes and phenotypes, and management projected $350 million in pro forma revenue against roughly $200 million for 2021. “This acquisition gives us the opportunity to accelerate the use of genomics as standard of care by providing a deeper menu of precision medicine solutions to our health system partners to better meet their clinical needs,” founder Eric Schadt said at the time, promising “an AI-driven advanced health intelligence company”. A $200 million private placement with Pfizer and other institutions helped fund it; Katherine Stueland, then GeneDx’s chief executive, joined Schadt as co-CEO and took a board seat.
The years after were less polished. The company took a $30.1 million revenue cut in August 2022 over a billing “dispute” with a payer, settling in 2023 for repayments of $42 million over four years; it laid off more than half its workforce, from 1,900 to 900, closed labs including its Connecticut flagship, rebranded from Sema4 to GeneDx in January 2023, and survived a Nasdaq delisting notice via a one-for-thirty-three reverse split. Then the stock ran: up more than 2,500% from the start of 2024, briefly worth about $2 billion, against the roughly $330 million the Grizzly Research short report says OPKO once accepted.
That report, published in February 2025, is the dispute’s current chapter, and notably it rests on insiders. Former employees allege the company inflated revenue through “code stacking”, billing insurers for services that miss the criteria, a practice they say has been prohibited since 2013, and a former vice president is quoted saying the scheme required the involvement of the CEO, the CFO and the chief technology officer. The short seller also points to an undisclosed whistleblower action, allegedly sham “independent” counselor entities steering patients to GeneDx tests, executives selling shares immediately on vesting without open-market purchases, and a former data platform, Centrellis, described by ex-staff as “all smoke and mirrors”. The company’s own marketing, it should be said, was never shy: “Exome/genome can be the best test for patients. They are also best for our business”.
It would seem unwise to treat a short seller’s brief as a verdict; Grizzly has its own position to protect, and the allegations of 25% revenue inflation are the firm’s estimate, unproven. But the pattern the report documents, billing disputes, settlements, mass layoffs, insider sales, is drawn from the company’s own record. A fraud accusation is a claim; a $42 million repayment is a fact. GeneDx now trades on the difference between them.
Sources
- Insiders Attest That GeneDx (Nasdaq: WGS) Is Actively Committing Widespread Fraud – Grizzly Research LLC
- Sema4 signals $623M acquisition of genetic testing provider GeneDx | Fierce Biotech
