Alphabet shares fell about 4% on July 16, 2026 after Bloomberg reported that Google's flagship Gemini 3.5 Pro model is months behind schedule, with coding performance falling short of internal expectations. Google announced the model at Google I/O in May 2026, saying it was in internal use and would be broadly available the following month. An Alphabet spokesperson told CNBC the company is "shipping quickly across a wide range of models while keeping them highly cost-effective," and is testing 3.5 Pro, an upgraded Flash model and others with partners. The delay lands after rival coding-focused releases: Meta's Muse Spark 1.1 and OpenAI's GPT-5.6 Sol, which Sam Altman said is 54% more token efficient on agentic coding tasks.