U.S. stock futures sent mixed signals as the fourth quarter began, with bond yields extending their largest quarterly increase since 1994. Alphabet shares rose 2.2% after Google launched Gemini 4 Argon, an artificial intelligence platform initially offered to selected cybersecurity organizations and government agencies. Google said Argon exceeded OpenAI and Anthropic systems in 13 of 19 industry-standard evaluations, including a 77.9% success rate on an extended software-development assessment. The platform is priced at $2 per million input tokens and $10 per million output tokens, with wider access planned after further security validation. Micron shares fell 0.4% despite robust fiscal fourth-quarter results, as investors questioned whether AI-related semiconductor demand can remain durable. Constellation Energy gained 3.7% after agreeing with Amazon to invest $3 billion over two decades to expand nuclear generation at a Maryland facility, adding about 190 megawatts of capacity. Vicor surged 12% after raising its third-quarter sequential growth forecast to 20% from 10%, citing royalty income from a newly disclosed licensing arrangement; Seeking Alpha projected growth above 30% based on royalties from Vicor's first non-exclusive license for vertical power delivery systems. Paramount Skydance declined 1.2%, while Warner Bros. Discovery was little changed after the companies confirmed an expected $81 billion merger completion date of October 6, subject to routine regulatory approvals. Madison Square Garden Sports edged higher after its board approved separating the New York Rangers from the New York Knicks, with completion scheduled for October 26. Inogen rose 8% after agreeing to sell its domestic oxygen rental operations to Rotech Healthcare for a potential $25 million, with completion projected in the fourth quarter of 2026. Inogen also signed a long-term procurement agreement with Rotech and increased its share-repurchase authorization by $15 million to $45 million. Corteva fell 64% after confirming plans to spin off its Crop Protection operations as Vylor, with shareholders receiving Vylor shares while retaining their Corteva holdings. The decline was described as a technical adjustment linked to the distribution, and the separation becomes effective October 1. Accenture, Acuity, McCormick, and Nike were scheduled to report quarterly results on Thursday.