Seven hundred cardiologists sat through REMS registration and training within weeks of a single drug’s launch in January. Cytokinetics had more than 125 field sales colleagues on the road by then, aimed at roughly 750 high-volume prescribers who together wrote about 80% of the country’s existing cardiac myosin inhibitor prescriptions, according to a report on the drug’s early rollout.
Cytokinetics is Armistice Capital‘s largest single-stock holding, and the launch that quarter tells only part of the story of what the fund did with its book. In the same three months it also bought a stake worth roughly the price of a cup of coffee.
A Drug Built to Beat a Head Start
The Food and Drug Administration approved Myqorzo, known generically as aficamten, on Dec. 19, 2025, for adults with symptomatic obstructive hypertrophic cardiomyopathy, a heart condition in which thickened muscle blocks normal blood flow. The approval rested on two trials. In SEQUOIA-HCM, aficamten produced a 1.74 mL/kg/min greater improvement in peak oxygen uptake than placebo at 24 weeks, a difference reported with a p-value of .000002, according to coverage of the trial data.
A second trial, MAPLE-HCM, found aficamten outperformed standard-of-care metoprolol on the same measure: patients on aficamten gained 1.1 mL/kg/min in exercise capacity over 24 weeks, while those on the beta-blocker lost 1.2 mL/kg/min, a between-group difference of 2.3 mL/kg/min with a p-value below .001, a review of the trial results found. Martin S. Maron, director of the Hypertrophic Cardiomyopathy Center at Lahey Hospital & Medical Center in Burlington, Massachusetts, told Healio, “Patients want to feel better and they want to function better, and aficamten is a therapy to make quality of life for patients much better.”
Bristol Myers Squibb had already been selling a cardiac myosin inhibitor of its own, Camzyos, for three years by the time Myqorzo reached pharmacy shelves in the second half of January 2026. Myqorzo’s advantage, according to analysts covering the launch, comes down to monitoring burden: it requires fewer echocardiograms, allows titration as early as two weeks and carries no drug-interaction monitoring requirement, industry analysis of the competitive dynamic found. Bristol Myers Squibb had not stood still on that front either. The FDA eased Camzyos’s own label on April 17, 2025, stretching the required echocardiogram interval from once every 12 weeks to every six months for patients who met certain heart-function criteria and loosening some drug-interaction contraindications, according to the company’s own announcement of the change.
Cytokinetics entered 2026 with about $1.2 billion in cash to fund its access push, and it set a commercial target of capturing more than half of new-to-brand prescriptions among patients starting a cardiac myosin inhibitor this year. Analysts have pegged the addressable market at $4.4 billion for the obstructive form of the disease alone, with another $1.2 billion in the non-obstructive form still unapproved for either drug.
By the quarter Armistice’s filing covers, Cytokinetics had booked $25.3 million in net Myqorzo revenue, $23 million of it in the United States and $2.3 million in Europe, and had dispensed the drug to about 1,500 patients, more than 80% of them on a paid prescription rather than a free trial, the company reported in its second-quarter results. Cash on hand had grown to $1.7 billion, up from $1.1 billion three months earlier. Chief Executive Robert I. Blum said the quarter’s results “demonstrate commercial launch momentum for MYQORZO alongside continued excellence for our development pipeline.” The company launched Myqorzo in Germany that same month, added a U.K. approval and a Netherlands reimbursement clearance effective Aug. 1, and had regulatory reviews underway in Canada, Switzerland, Hong Kong and Taiwan.
Bristol Myers Squibb’s own quarter put that number in perspective. Camzyos generated $416 million in revenue over the same three months, up 59% from a year earlier, a gain executives credited to continued promotional efforts, new prescriber additions and deeper penetration into community-based cardiology practices, according to the company’s earnings call. Bristol Myers Squibb executives also said a Phase 3 study testing Camzyos in the non-obstructive form of the disease, the population still unapproved for either drug, was expected to begin before the end of the year.
The Position That Anchors the Book
None of that commercial buildout happens without patients, but for Armistice, the more immediate number is the one on its own balance sheet. The fund holds Cytokinetics shares worth about $233 million, 2.8% of its reported portfolio, according to fund-tracking data compiled by StockZoa.
Only two positions outrank it: put options on the SPDR S&P 500 ETF Trust and the iShares Russell 2000 ETF, which together account for more than half of everything Armistice reported owning. Agios Pharmaceuticals and Madrigal Pharmaceuticals follow Cytokinetics, at 2.4% and 1.9% of the portfolio, respectively, rounding out the fund’s five largest disclosed positions.
Armistice is one of roughly 449 institutional holders in Cytokinetics, a group that includes BlackRock, Fidelity, Vanguard and T. Rowe Price, the same report on the fund’s holding found. Steven Boyd founded Armistice Capital in 2012, and the fund’s stated approach, long/short and value-oriented, covers everything from a stake the size of its Cytokinetics position down to positions barely worth the paperwork required to disclose them.
Three Trades That Cost Almost Nothing to Make
That range showed up starkly in the same quarter’s filings. Armistice picked up 5,096,251 shares of Aridis Pharmaceuticals, a late-stage biopharmaceutical company developing monoclonal-antibody immunotherapies for life-threatening infections, at a reported price of $0.0001 a share, a transaction worth roughly $510 in total, according to a filing summary.
The pricing reflects the kind of deeply distressed or restructuring-driven terms that show up when a small biotech is running low on runway, not a conventional market purchase. The stake came to 11.43% of Aridis’s stock and did not move Armistice’s own portfolio weighting by a measurable amount.
Armistice went the other direction with Autolus Therapeutics, a U.K.-based developer of CAR T-cell therapies whose Aucatzyl won FDA approval on Nov. 8, 2024, for relapsed or refractory B-cell precursor acute lymphoblastic leukemia, the company announced at the time. The fund sold 800,000 shares at $1.60 apiece this quarter, trimming its position by just over 5% and leaving it with 15 million shares, equal to 5.64% of Autolus’s stock and 0.43% of Armistice’s own portfolio, a separate filing summary shows. By August, Autolus shares had climbed 54% past that sale price, to $2.465, though the stock remained down more than 91% from its 2018 initial public offering.
A third position went further still. Armistice sold 50,975.5625 shares of Calidi Biotherapeutics, a developer of oncolytic virus therapies for solid tumors and glioma, at $2.72 apiece, cutting the stake by 92.79% and leaving just 3,961.9375 shares on the books, according to a filing recap. What remained still equaled 4.99% of Calidi’s stock, a reminder of how small the company itself had become; Calidi traded at $1.34 a share by the time the filing was reported, down roughly 99.98% from its 2023 initial public offering.
What One Filing Day Contains
All three trades, along with the Cytokinetics disclosure, were reported as of the same date, June 30, 2026. Read next to each other, they describe a fund running two portfolios under one name.
One portfolio is built around a small number of substantial, durable positions in companies with real revenue and, in Cytokinetics’ case, a national sales force and a commercial target measured in prescription share. The other consists of dozens of positions in companies whose entire market value can be smaller than the cost of the paperwork required to disclose an ownership stake in them, bets that can be built or unwound inside a single quarter without leaving much trace in the fund’s overall numbers.
Cytokinetics will spend the rest of 2026 trying to convert its cardiology sales force into market share against an established competitor that has already adjusted its own label once in response to the threat. Aridis, Autolus and Calidi will keep trading at whatever prices their own investors assign them, largely independent of what Armistice does next. The fund’s position in all four is disclosed in the same document, filed on the same day, under the same address on Madison Avenue in Manhattan, a business listing for Armistice Capital South LLC shows. Nothing in that filing says which of the four, if any, Armistice still holds by the time it files again.