4DMedical Shares Pull Back as Profit Taking Cools Rally, and RSI

After one of the most spectacular runs in recent ASX history, 4DMedical shares (ASX: 4DX) have entered a sharp correction phase, closing Friday down 8.75% and finishing the week 14.12% lower as traders lock in gains from a rally that has delivered returns of almost 2,000% over the past twelve months. A glance at the one year chart below, and the momentum is clear to see.

The 4DMedical share price has now retraced 22.6% from the freshly minted high of last week, though 4DX remains an extraordinary 54% higher over the past month alone.

The pullback has brought the shares back to test the 20-day simple moving average, a technical support level closely watched by momentum traders. The relative strength index has cooled from overbought territory above 70 into the mid-50s, suggesting the frenetic buying pressure that characterised recent sessions has dissipated.

What Has Been Driving the Rally in 4DX?

The explosive re-rating of 4DMedical shares stems from a sequence of transformational regulatory and commercial milestones achieved over the past nine months. In early September 2025, the company secured FDA 510(k) clearance and US Centers for Medicare & Medicaid Services reimbursement approval for its CT:VQ ventilation-perfusion lung imaging software. This twin regulatory breakthrough removed the two primary barriers to large-scale US adoption, allowing hospitals to bill for CT:VQ exams under existing reimbursement structures without requiring additional nuclear medicine infrastructure.

The FDA clearance triggered an immediate market re-rating, with the shares surging more than 44% in a single session. CT:VQ converts standard chest CT scans into quantitative ventilation and perfusion maps using artificial intelligence, enabling hospitals without specialised nuclear medicine departments to offer advanced V/Q diagnostics for conditions including pulmonary embolism, COPD and asthma.

Along with the FDA approval, 4DMedical secured a A$10 million strategic investment from Pro Medicus, one of Australia’s most successful medical imaging software companies. The endorsement from Pro Medicus, which has itself delivered multi-bagger returns to shareholders through its radiology PACS platform, was interpreted by markets as powerful third-party validation of 4DMedical’s technology and business model.

More recently, the company completed a substantial A$150 million institutional capital raise to fund the accelerated US rollout of CT:VQ. The placement, conducted in the first quarter of 2026, was supported by strong institutional demand and followed an earlier A$30.2 million options underwriting agreement announced in December 2025. Combined, these funding initiatives have equipped 4DMedical with what management describes as a war chest to finance sales expansion, site deployment and platform scaling across the United States.

Flagship Customer Wins

The commercial validation of the regulatory approvals arrived swiftly. Within two months of FDA clearance, Stanford University became the first major US academic medical centre to sign a commercial contract for CT:VQ, committing to analyse up to 20,000 scans per year. The Stanford agreement established a recurring revenue model and provided a prestigious reference site for the technology.

In early 2026, 4DMedical added the Mayo Clinic to its customer roster, triggering another sharp intraday rally exceeding 30%. The Mayo contract reinforced the narrative that CT:VQ is gaining acceptance among tier-one US healthcare institutions and validated the company’s decision to raise substantial growth capital.

Beyond the United States, 4DMedical is expanding its lung health screening programme in Brazil in partnership with AstraZeneca, rolling out from the initial Hospital Madre Teresa site to five additional hospitals expected to generate approximately 38,000 CT scans annually. The company has also signed a Cooperative Research and Development Agreement with the West Los Angeles VA Medical Center, positioning the technology for potential adoption across the vast Veterans Affairs health system.

Index Inclusion and Technical Factors

Adding fuel to the rally, S&P Dow Jones Indices announced in March 2026 that 4DMedical would be added to the S&P/ASX All Ordinaries Index as part of the quarterly rebalance, effective 23 March. Index inclusion typically generates forced buying from passive funds and benchmark-constrained managers, contributing to upward price momentum. The timing of the recent correction suggests that index-related demand may have been exhausted, removing a technical tailwind and allowing profit-taking to dominate.

From a technical perspective, the recent pullback has allowed overextended indicators to normalise.

The RSI retreating from overbought levels and the share price returning to the 20-day moving average present a potential inflection point. Bulls will be watching for a bounce from this support level as confirmation that the underlying uptrend remains intact.

A failure to hold the 20-day average could signal a deeper mean reversion toward the 50-day or even 200-day moving averages, which sit substantially lower given the parabolic nature of the recent move.

Valuation and Execution Risk

The central tension in 4DMedical’s investment thesis revolves around valuation versus execution. The company now commands a market capitalisation that implies substantial future revenue and profit streams, yet current revenue remains in the single-digit millions. Markets have effectively priced in a scenario where CT:VQ and the broader imaging platform achieve widespread adoption across hundreds of US hospitals, generating high-margin recurring software revenue.

Bears argue that this optimistic scenario is far from guaranteed. Hospital procurement cycles are notoriously long and complex, involving multiple stakeholders, IT integration challenges and clinical workflow changes. Competing technologies and established players in the lung imaging space may impede market share gains. The requirement for ongoing capital raises underscores the distance to self-funding operations and the binary nature of the execution risk.

Bulls counter that the regulatory and reimbursement hurdles, historically the highest barriers in medical technology, have been cleared. With FDA approval, CMS reimbursement, flagship reference customers and a fully funded balance sheet, 4DMedical is positioned to capture a significant share of what management describes as a multi-billion-dollar addressable market. The technology’s ability to leverage existing CT infrastructure without requiring capital equipment purchases lowers the barrier to adoption and accelerates the sales cycle relative to traditional medical devices.

What Comes Next

The coming weeks will prove critical in determining whether 4DMedical’s share price consolidates at current levels before continuing on upwards, or whether there is more meaningful pause to come. For now, 4DMedical remains one of the ASX’s most compelling and polarising stories, a company that has delivered life-changing returns to early believers while presenting substantial risk to those entering at current valuations.

The recent pullback, while sharp, represents a modest correction within the context of an extraordinary twelve-month run, and the technical setup suggests the battle between bulls and bears is far from resolved. Whether the 20-day moving average holds as support, or gives way to a deeper retracement, will likely set the tone for the next phase of this remarkable market story.

Analyst Summary: Bull and Bear Cases