One signature away. Expected within months.

The central question is not whether Google will win in Luxembourg. It is whether the market has ever seriously tried to value Alphabet without its default placement.

Google filed appeals on September 29, 2026 before the EU’s General Court against two Digital Markets Act specification decisions: one on interoperability for AI services on Android, and one on sharing Google Search data. Google has argued that the mandated changes raise risks for user privacy and security. One decision requires Google to implement most Android interoperability changes by August 2027; the other requires it to begin implementing search-data sharing within six months of the decision, by January 2027. This is not a procedural footnote. It is the most direct regulatory attack yet on the mechanism that built Google’s business.

Google controls the default search setting on browsers representing more than 87% of U.S. web traffic, combining Chrome, Safari, Firefox, and Samsung Internet. Google’s search share reaches 95.52% on mobile and 84.49% on desktop as of May 2026. The mobile figure traces almost entirely to one thing: being the pre-installed default on Android. The EU order targets precisely that.

The bear case is structural, not cyclical. The Commission said the Android changes would give competing AI assistants access to features currently available only to Google’s own Gemini, allowing users to activate a rival assistant by voice or ask it to carry out tasks in other apps. OpenAI and Perplexity are the obvious beneficiaries. Neither currently gets that level of Android integration. A court win for Google delays the timeline; a loss accelerates the competitive clock considerably.

The UK is already moving without waiting for Luxembourg. The Competition and Markets Authority published strengthened proposals on September 23, 2026 and is consulting on them until October 9, with a final decision expected by the end of the year. AI assistants such as ChatGPT and Perplexity would appear on the same choice screen alongside search engines if they meet technical and security criteria. When the CMA announced those proposals six days ago, the claim that the threat to Google’s core search distribution advantage sent GOOG down 3.71% on September 23 is not supported by widely used historical price records; GOOG was down about 3.6% that day. That single-session move on a proposal that is still in consultation is an early read on how badly investors are mispricing the default-erosion scenario.

The bull case rests on two things: legal delay and product quality. DMA appeals routinely take years to resolve, and Google’s lawyers have been here before. The majority of the EU’s DMA decisions have so far been appealed, as Big Tech firms seek clarity on the law’s application. On the quality argument, Google will point out that its lead over Bing in May 2026 sits at 85.36 percentage points, roughly the same gap recorded a year earlier despite the AI search shake-up. Users who want Google still find it. Losing the default, the argument goes, does not mean losing the user.

What that argument misses is mobile. The mobile gap traces directly to default search placement on Android handsets and Safari on iOS. Desktop users switch browsers. Mobile users almost never change a pre-installed default unless they are prompted. The EU’s July 2026 decisions, and the CMA’s annual re-prompt proposal, are specifically designed to create that moment of friction. Defaults tend to stick because most people never revisit them. A prompt every year gives people a regular moment to switch without digging through settings.

There is a second-order consequence almost no one is discussing: the search data order may matter more than the Android order. The European Commission said Google must start implementing search data sharing by January 2027 to rebalance the playing field. That data is the training fuel for every AI search rival. Perplexity and OpenAI have built competitive products without it. Access to Google’s query corpus at scale would compress the quality gap that has been Google’s last defensible moat.

Stocks to Watch

• Alphabet (GOOGL). The direct target. Advertising drives most of Alphabet’s $402.8 billion in consolidated 2025 revenue, and the overwhelming share of that ties back to search intent captured through default placement. Every point of mobile share at risk is not an abstraction; it is a direct revenue exposure.
• Microsoft (MSFT). Bing is the structurally-positioned beneficiary of any European choice screen that displaces Google. Copilot integration gives Microsoft a product ready to absorb redirected users in a way it simply did not have five years ago.
• OpenAI / Perplexity. Both remain private, but the CMA is moving toward treating Android and Chrome as regulated distribution points for search choice that can include AI assistants. A default slot on Android is the kind of distribution event that changes a company’s trajectory overnight.