Form 4: Atlas Venture Exits IAS Post-Merger at $10.30/Share

Atlas Venture Fund VIII, L.P. and its affiliates disposed of all their 22.7 million shares in Integral Ad Science Holding Corp. following its merger into a wholly-owned subsidiary of Igloo Group Parent, Inc. for $10.30 per share.

Summary

• Atlas Venture Fund VIII, L.P., Atlas Venture Associates VIII, L.P., and Atlas Venture Associates VIII, Inc. (collectively, the "Reporting Persons"), who were 10% owners and had director representation, reported the disposal of their entire holdings in Integral Ad Science Holding Corp. (IAS).
• The disposal occurred on December 23, 2025, as a result of a merger pursuant to an Agreement and Plan of Merger dated September 24, 2025.
• Under the Merger Agreement, Igloo Group Acquisition Company, Inc., a wholly-owned subsidiary of Igloo Group Parent, Inc., merged with and into IAS, with IAS surviving as a wholly-owned subsidiary of Igloo Group Parent, Inc.
• At the effective time of the merger, each share of IAS common stock owned by the Reporting Persons was automatically cancelled, extinguished, and converted into the right to receive $10.30 in cash, without interest.
• The Reporting Persons disposed of 22,722,770 shares of common stock, $0.001 par value, at a price of $10.30 per share.
• Following the reported transaction, the Reporting Persons beneficially own 0 shares of Integral Ad Science Holding Corp. common stock.

Sentiment

Score: 7

Explanation: The filing reports the successful completion of a merger where a significant shareholder (the reporting entity) exited its position for a fixed cash price, indicating a definitive and positive realization of investment for them. For IAS shareholders, it represents a clear liquidity event.

Positives

• The Reporting Persons successfully exited their investment in Integral Ad Science Holding Corp. at a fixed cash price of $10.30 per share, realizing a definitive return.
• The merger provided a clear liquidity event for all shareholders of Integral Ad Science Holding Corp., converting their equity into cash.

Negatives

• Integral Ad Science Holding Corp. ceased to be an independent publicly traded entity, becoming a wholly-owned subsidiary of Igloo Group Parent, Inc.
• The Reporting Persons no longer hold any equity interest in Integral Ad Science Holding Corp., eliminating future upside potential from the company's performance.

Risks

• The Reporting Persons (Atlas VIII, AVA VIII LP, and AVA VIII Inc.) disclaim beneficial ownership of all shares except to the extent of their pecuniary interest, if any, and state that the report shall not be deemed an admission of beneficial ownership for Section 16 or any other purpose.

Future Outlook

The filing reports a completed transaction and does not provide any forward-looking statements or guidance regarding Integral Ad Science Holding Corp.'s future operations, as it is now a wholly-owned subsidiary.

Industry Context

This transaction represents a consolidation event within the ad tech and digital measurement industry, where a publicly traded company, Integral Ad Science, was acquired and taken private. Such mergers are common as companies seek to gain market share, integrate technologies, or achieve operational synergies.

Corporate Governance

Related Party Transactions

• Atlas Venture Fund VIII, L.P. was a 10% owner and had director representation on the board of Integral Ad Science Holding Corp. Their disposal of all shares was part of a broader merger transaction, which, while not a direct related-party transaction in the traditional sense of a special deal, represents the exit of a significant insider.

Stakeholder Impact

• Shareholders of Integral Ad Science Holding Corp. received $10.30 per share in cash, providing a definitive return on their investment.
• Employees of Integral Ad Science Holding Corp. will now be part of the Igloo Group Parent, Inc. organization, potentially leading to changes in corporate culture, structure, and benefits.
• Customers and suppliers of Integral Ad Science Holding Corp. may experience changes in operations, product offerings, or business relationships as the company integrates with its new parent.

Next Steps

• Integral Ad Science Holding Corp. will operate as a wholly-owned subsidiary of Igloo Group Parent, Inc., implying integration into the parent company's structure and operations.

Key Dates

Keywords

Integral Ad Science, IAS, Atlas Venture, Merger, Acquisition, Form 4, Beneficial Ownership, Equity Disposal, Igloo Group Parent, Cash Consideration