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

Atlassian Co-Founder and CEO Michael Cannon-Brookes sold 7,665 shares of Class A Common Stock on December 5, 2025, as part of a pre-arranged 10b5-1 trading plan.

Summary

• Michael Cannon-Brookes, Co-Founder, CEO, Director, and 10% Owner of Atlassian Corp, sold a total of 7,665 shares of Class A Common Stock.
• The sales occurred on December 5, 2025, through multiple transactions at weighted-average prices ranging from $156.9515 to $164.0276 per share.
• These transactions were executed under a Rule 10b5-1 trading plan that was adopted on February 20, 2025.
• Following these sales, Michael Cannon-Brookes indirectly beneficially owns 130,305 shares of Class A Common Stock, held by CBC Co Pty Limited as trustee for the Cannon-Brookes Head Trust.

Sentiment

Score: 5

Explanation: The sale of shares by a key insider, Michael Cannon-Brookes, is generally viewed with slight caution. However, the execution under a pre-arranged Rule 10b5-1 trading plan reduces the negative implication, as these sales are scheduled in advance and not typically indicative of new, adverse company developments.

Positives

• The sales were conducted under a pre-arranged Rule 10b5-1 trading plan, indicating a planned divestment rather than a reaction to new, negative information.

Negatives

• Insider selling, even under a 10b5-1 plan, reduces the insider's direct equity stake in the company.
• The total value of shares sold is significant, reflecting a substantial divestment by a key executive and major shareholder.

Risks

• While executed under a 10b5-1 plan, significant insider selling can sometimes be perceived by the market as a lack of confidence, potentially leading to negative sentiment or downward pressure on the stock price.

Future Outlook

NA

Industry Context

This filing is a routine disclosure of insider trading activity and does not provide specific industry context or trends. It reflects an individual executive's portfolio management rather than a company-wide strategic move.

Related Party Transactions

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

Stakeholder Impact

• Shareholders may interpret the insider selling as a slight negative signal, though the 10b5-1 plan mitigates this. The reduction in insider ownership could be seen as a minor decrease in alignment, but the remaining substantial indirect holdings still represent significant alignment.

Key Dates

Recommendation

The insider selling by Michael Cannon-Brookes, while notable, was conducted under a pre-arranged 10b5-1 trading plan. This suggests a planned portfolio diversification or liquidity event rather than a reaction to new, negative company-specific information. Given the routine nature of such transactions under a 10b5-1 plan, it does not provide a strong signal for a 'buy' or 'sell' recommendation based solely on this filing. Investors should 'hold' and consider broader company fundamentals and market conditions.

Keywords

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