SCHEDULE: Artisan Partners Amends iRhythm Holdings Stake

Artisan Partners Asset Management Inc. and its affiliates have updated their beneficial ownership in iRhythm Holdings, Inc. to 4.7% of common stock.

Summary

• Artisan Partners Asset Management Inc. and its affiliates (Artisan Partners Holdings LP, Artisan Investments GP LLC, and Artisan Partners Limited Partnership) collectively beneficially own 1,511,992 shares of iRhythm Holdings, Inc. common stock.
• This represents 4.7% of the total class of securities, based on 32,219,143 shares outstanding as of October 23, 2025.
• The reporting persons have shared voting power over 1,314,008 shares and shared dispositive power over 1,511,992 shares.
• The filing indicates that the securities were acquired and are held in the ordinary course of business and not for the purpose of changing or influencing control of iRhythm Holdings, Inc.
• This document is an Amendment No. 2 to a Schedule 13G filing.

Sentiment

Score: 5

Explanation: StockSavvy.ai views this as a neutral filing, primarily a disclosure of an updated passive ownership stake. The slight reduction in percentage ownership is a minor point but does not inherently signal a strong positive or negative outlook for iRhythm Holdings.

Positives

• A significant institutional investor, Artisan Partners, maintains a substantial stake in iRhythm Holdings, Inc., indicating continued confidence in the company.
• The filing explicitly states the shares are held in the ordinary course of business, not for control, suggesting a passive investment strategy.

Negatives

• Artisan Partners' beneficial ownership has decreased to 4.7% of iRhythm Holdings, Inc. common stock, implying a reduction from a previous position that was at or above the 5% Schedule 13G filing threshold.

Risks

• The filing itself does not detail specific risks related to iRhythm Holdings, Inc.'s operations or financial health.
• A reduction in a significant institutional investor's stake could be perceived as a potential risk by other investors, signaling a possible shift in investment strategy or outlook by Artisan Partners.

Industry Context

StockSavvy.ai notes that institutional ownership changes, particularly from prominent asset managers like Artisan Partners, are closely watched in the healthcare technology sector. While this filing indicates a passive stake, any significant adjustment in holdings can influence market perception of companies like iRhythm Holdings, which operates in the competitive medical device and diagnostic space.

Stakeholder Impact

• Shareholders: Existing shareholders may note the updated position of a significant institutional investor. A reduction in stake could lead to questions about Artisan Partners' long-term view, while continued holding indicates some level of confidence.
• Management: Management of iRhythm Holdings, Inc. will be aware of the updated ownership structure, particularly the passive nature of Artisan Partners' investment, which suggests no immediate intent to influence corporate control.

Key Dates

Recommendation

The filing is a routine disclosure of an updated passive ownership stake by a major institutional investor. While the percentage has decreased to below 5%, it does not provide sufficient new information about iRhythm Holdings' operational or financial performance to warrant a 'buy' or 'sell' recommendation. Investors should 'hold' and monitor future company performance and further ownership changes.

Keywords

iRhythm Holdings, Artisan Partners, Schedule 13G, Beneficial Ownership, Common Stock, Institutional Investor, Medical Devices, Healthcare Technology, SEC Filing