Form 4: Atlassian Co-Founder Sells Shares Under 10b5-1 Plan

Atlassian Co-Founder and CEO Michael Cannon-Brookes reported the sale of 7,665 Class A Common Stock shares on December 12, 2025, under a pre-arranged 10b5-1 trading plan.

Summary

• Michael Cannon-Brookes, a Director, 10% Owner, and CEO/Co-Founder of Atlassian Corp (TEAM), reported transactions on December 12, 2025.
• A total of 7,665 shares of Class A Common Stock were disposed of through multiple sales.
• The sales were executed at weighted-average prices ranging from $161.1487 to $164.01 per share.
• These transactions were conducted pursuant to a Rule 10b5-1 trading plan adopted by Mr. Cannon-Brookes on February 20, 2025.
• Following these transactions, Mr. Cannon-Brookes beneficially owns 91,980 shares indirectly through CBC Co Pty Limited as trustee for the Cannon-Brookes Head Trust.

Sentiment

Score: 5

Explanation: The sentiment is neutral. While insider selling can sometimes be perceived negatively, the execution under a pre-arranged Rule 10b5-1 plan indicates a scheduled, non-discretionary transaction, mitigating concerns about immediate company-specific negative news.

Positives

• The transactions were executed under a Rule 10b5-1 trading plan, indicating a pre-scheduled sale rather than a reaction to new, undisclosed information.

Negatives

• Insider selling, even if pre-planned, can sometimes be viewed with caution by some investors, potentially signaling a lack of conviction, though the 10b5-1 plan mitigates this interpretation.

Risks

• Potential for negative investor sentiment if the sale is misinterpreted as a lack of confidence in the company's future performance, despite the existence of a Rule 10b5-1 plan.

Future Outlook

This filing does not contain any forward-looking statements or guidance regarding the company's future performance or outlook.

Industry Context

This insider transaction is a routine disclosure and does not inherently provide insights into broader industry trends or competitive landscape for the software development and collaboration tools sector.

Related Party Transactions

• The shares beneficially owned following the reported transactions are held indirectly by CBC Co Pty Limited as trustee for the Cannon-Brookes Head Trust, which is a related party to the reporting person.

Stakeholder Impact

• Shareholders: May observe the insider sale, but the pre-planned nature under a 10b5-1 plan typically reduces concerns about its implications for company fundamentals.

Key Dates

Keywords

Atlassian, TEAM, Michael Cannon-Brookes, Insider Trading, Form 4, Stock Sale, 10b5-1 Plan, Director, CEO, Co-Founder