Zscaler Inc. (NASDAQ: ZS) experienced a dramatic reversal in after-hours trading on Thursday, September 3, 2026, as investors digested the cybersecurity firm's fiscal fourth-quarter results. The stock initially surged nearly 12% in response to a solid revenue beat, but the rally quickly faded as concerns over a significant drop in free-cash-flow margin took center stage.
Shares climbed to a peak of $199.00 shortly after the earnings release, representing an 11.9% increase from the closing price of $177.80. However, by 16:30:15 EDT, the price had pulled back to $179.80, leaving the stock just 1.1% higher than its regular-session close. The rapid reversal highlights the market's sensitivity to profitability metrics in the capital-intensive cybersecurity sector.
Revenue Growth Meets Expectations, but Cash Conversion Deteriorates
The company reported fiscal fourth-quarter revenue of $898.2 million, a 25% year-over-year increase that exceeded the top end of its guidance by 2.3%. Annual recurring revenue (ARR) reached $3.771 billion, also up 25% from the prior year. However, when excluding the contribution from Red Canary, an acquisition completed earlier this year, organic ARR growth was a more modest 20%.
The divergence between headline and organic growth metrics is likely to fuel debates about the quality of Zscaler's expansion. Red Canary contributed $141 million to ARR, representing 3.7% of the total. Investors have historically valued Zscaler for its high-margin, subscription-based model, and any sign of deceleration in core growth could weigh on the stock's premium valuation.
Cash-Flow Margin Slumps as Expenditures Triple
The most concerning data point for shareholders was the dramatic deterioration in free-cash-flow (FCF) margin. In the fiscal fourth quarter, FCF plunged 65% to $60.8 million, down from $171.9 million in the same period last year. The FCF margin contracted to just 7%, compared to 24% a year earlier.
The primary driver of this decline was a near-tripling in capital expenditures and internal-use software costs, which totaled $218.5 million. This surge in spending reflects Zscaler's investments in data center capacity and product development, particularly in artificial intelligence (AI) and machine learning capabilities.
Chief Executive Jay Chaudhry described AI as "one of the most significant opportunities" in the company's history, citing increased demand for securing AI agents and models. Chief Financial Officer Kevin Rubin highlighted unprecedented large-deal activity and improved sales productivity, noting that growth was also supported by non-seat-based offerings.
Guidance Suggests Slowing Growth Ahead
Looking forward, Zscaler provided guidance that points to a deceleration in growth. For the first quarter of fiscal 2027, the company expects revenue in the range of $935 million to $939 million, indicating approximately 19% year-over-year growth. The non-GAAP operating margin is projected at 23%.
For the full fiscal year 2027, revenue guidance targets $3.923 billion, representing growth of around 17% from fiscal 2026 levels. ARR guidance also suggests roughly 17% growth, a notable slowdown from the 25% reported in fiscal 2026.
The full-year report underscores the trade-off facing the company. While revenue increased 25% in fiscal 2026, the free-cash-flow margin declined to 23% from 27% in the prior year, reflecting the heavy investment phase.
Balancing Risks and Opportunities
Zscaler's management remains optimistic about the future, pointing to potential cross-selling opportunities from the Red Canary acquisition and the possibility that data-center spending will decline once current deployments are completed. However, risks remain, including weaker organic ARR growth, integration challenges with acquisitions, and fluctuating capital expenditures that could pressure cash flow.
The after-hours volatility also highlights the limited liquidity in extended trading, which can amplify price swings. As the market heads into a holiday week, investors will be closely watching how Zscaler's stock performs in regular trading on Friday and whether the company can reassure shareholders about its path to improved cash conversion.
For now, the focus is on whether Zscaler can translate its 17% growth guidance into more consistent free cash flow, rather than a short-lived surge in the share price. The company's ability to balance growth investments with profitability will be crucial in maintaining investor confidence.
