iRhythm delivered a profitability blowout wrapped around a growth problem. Adjusted EPS of $0.82 crushed the $0.02 consensus, a 4000.0% surprise, and swung from an adjusted loss of $0.06 a year ago, which works out to 1466.7% earnings growth. Revenue of $221.59 million grew 14.9% but slipped 0.3% short of the $222.27 million consensus. That is the central tension: margins are expanding faster than anyone modeled, while the top line has decelerated sharply. This quarter ended a streak of seven straight 20%-plus growth quarters, following 27.1% in Q4 FY25, 25.7% in Q1 and 20.1% in Q2.

The quality of the beat deserves scrutiny on both sides. Gross margin reached 74.2%, up 310 basis points, but roughly 140 basis points came from a one-time tariff refund of about $3.1 million. Adjusted EBITDA margin hit a record 23.1%, versus 19.3% in Q2 and 7.1% in Q1. That was driven by real cost discipline: adjusted operating expenses fell to $138.6 million from $141.4 million despite double-digit revenue growth. GAAP results look very different. The net loss widened to $29.9 million, or $0.90 per share, from $5.2 million, mainly because of $49.8 million in litigation settlements tied to the Baxter patent dispute and a securities class action. Free cash flow was negative $11.5 million, including $50 million of Baxter settlement payments. Those items are largely nonrecurring, but they are real cash.

The call revealed where the growth went. Zio Monitor beat internal expectations, and innovative channels remained the fastest-growing segment. Zio AT, however, was flat year over year after growing more than 50% in 2025. Earlier in the year, management had expected it to grow faster than the company overall. Management blamed new accounts deferring onboarding until VitalConnect is integrated, and expects the drag to last one to two quarters. The model is less forgiving: Zio AT flat sequentially in Q4, down about 10% year over year, and flat again in 2027. The internally developed Zio MCT also slipped. After three straight calls reaffirming a first-half 2027 launch, the plan is now only an FDA submission in 2027 as resources shift to the acquisition. Analysts pressed on whether the AT disruption was foreseen in diligence. Management's tone cooled from Q2's 'record quarter' language to repeated assurances that it would 'not get ahead of ourselves.'

The guidance raise is less generous than it looks. Full-year revenue guidance moved to $890-$895 million from $875-$885 million, but that includes about $16 million of VitalConnect revenue. On an organic basis, the implied range of roughly $874-$879 million is flat to slightly below the prior outlook. Implied Q4 organic growth is only about 10-12%. Adjusted EBITDA margin guidance rose to 15.5%-16.0%, and pricing is now a modest tailwind rather than flat.

The forward catalysts are substantive. VitalConnect closed October 5, well ahead of the year-end target, bringing an immediate FDA-cleared MCT product with a run rate of about $65 million. Vital Patch is slated to sell through roughly 200 reps instead of about 30 by mid-Q1 2027. Management also outlined an initial 2027 framework: about $1 billion of organic revenue, gross margin above 70%, and adjusted EBITDA margin of at least 15%. Additional support comes from:

• a pediatric Zio Monitor 510(k) filing;
• the EXCALIBUR real-world data;
• a next-generation AI algorithm due in early 2027;
• a new $300 million revolver.

Bears still have legitimate ammunition. The FDA warning letter remains open with no reinspection timing, and the integration carries execution risk in EHR connectivity, supply-chain scaling and state-level payer coverage.

The market had already moved ahead of this report. Shares hit a 52-week low of $100.70 on October 8, then rallied about 33% to an inter-earnings high of $138.36 on November 4, the day before the release. They entered the print at $134, just 3.2% below that high and 9.8% above the 200-day moving average. Even so, the stock is only 1.8% above its opening price after the August report, so the round trip has netted little. Investor sentiment swung meaningfully, from -0.21 to +0.11, moving from mildly skeptical to modestly positive. Momentum and AVWAP trend readings are positive. That setup leaves less cushion for a quarter in which the organic growth narrative weakened.

The bottom line is that iRhythm proved its margin story decisively, but the growth story got murkier. Record EBITDA margins and an accelerated VitalConnect close are genuine positives. Against them, Zio AT has stalled, Zio MCT has been delayed, Q4 organic growth is set to slow to the low double digits, and the guidance raise is largely acquired revenue. With shares rebounding into the report and sentiment turning positive, investors now need VitalConnect integration to restart AT growth on schedule rather than merely fill the gap.