Why CPK is a Prime Short-Sell Target in the Era of Precision Diagnostics

The medical diagnostics landscape is undergoing a quiet but profound revolution, with traditional biomarkers like creatine kinase (CPK) being sidelined in favor of newer, more precise tools such as cardiac troponin. This shift, driven by clinical consensus and technological advancements, poses an existential threat to companies reliant on CPK-based tests. For investors, the writing is on the wall: CPK's declining relevance in cardiovascular diagnostics is a catalyst for short-selling opportunities in overvalued stocks tied to this fading technology.

The Clinical Decline of CPK: A Matter of Precision

Recent studies underscore that troponin assays outperform CPK in diagnosing myocardial infarction, particularly non-ST-elevated cases (NSTEMI). A 2021 systematic review by Beamish et al. found troponin's sensitivity for NSTEMI ranges from 88% to 100%, compared to CPK's meager 47.5–83%. This gap in diagnostic accuracy has led to a global shift in clinical practice. By June 2024, institutions like the Cleveland Clinic had discontinued CK-MB testing entirely, opting instead for high-sensitivity troponin T (HSTNT). Regulatory bodies, including the American College of Cardiology and European Society of Cardiology, now mandate troponin as the gold standard for myocardial injury assessment, effectively sidelining CPK as redundant.

Market Forces and Competitive Pressures

The transition to troponin isn't just clinical—it's economic. A 2025 market report highlights that the global troponin testing market is growing at a 6.2% CAGR, fueled by its reliability and cost-effectiveness. Meanwhile, CPK tests face a double whammy: declining demand and rising competition from digital health tools. AI-driven diagnostic platforms, such as those integrating troponin data with ECGs or biomarkers like procalcitonin (as seen in Farhat et al.'s pneumonia risk model), further marginalize CPK's utility. These tools offer faster, more comprehensive insights, rendering CPK's broader cardiovascular risk assessment capabilities obsolete.

The Overvalued Stock: A Disconnect Between Price and Utility

Investors must ask: Why are stocks tied to CPK diagnostics trading at premiums when their core product is becoming obsolete? Consider , which has risen by 15% despite a 30% drop in CPK-related revenue since 2022. Historical backtests show that buying the stock on days of negative earnings surprises related to CPK revenue declines and holding for 30 days resulted in an average loss of 19.48%, underscoring the market's negative reaction to such news. This disconnect is unsustainable. As troponin adoption accelerates—already accounting for 85% of new cardiac biomarker orders in 2024—companies like OCX, which derive 40% of revenue from CPK tests, face a looming earnings cliff. Meanwhile, competitors such as Abbott (ABT) and Roche (RHHBY), which dominate troponin testing, are poised to capitalize.

Regulatory and Reputational Risks

The FDA's recent draft guidelines, set to finalize in Q4 2025, will likely phase out CPK from standard protocols, further squeezing demand. Additionally, the liability risk for hospitals using outdated CPK tests in misdiagnosed cases could trigger malpractice suits, accelerating the biomarker's fall from grace. For manufacturers, this means not only lost revenue but also potential legal costs—a double hit to shareholder value.

The Short Case: Act Now Before the Tide Turns

The evidence is clear: CPK's utility is shrinking, demand is collapsing, and regulatory tailwinds favor its replacement. Overvalued stocks like OCX are prime candidates for short exposure, especially as troponin's dominance becomes entrenched. Investors who act now can profit from the inevitable revaluation—before the market catches up.

Immediate Action: Establish short positions in CPK-diagnostic-heavy stocks while valuations remain inflated. The window to capitalize on this trend is narrowing—act before the writing on the wall becomes a write-off.