Chip Stocks Surge on Meta's AI Agent as Nasdaq's RSI Hits 81 and Oil Slides Despite Attack on Riyadh

On September 18, 2026, the loudest move of the session came from chipmakers, not from the index averages: Arm jumped 13%, Intel rose 12% and AMD gained 9% after Meta Platforms unveiled "Muse," a new AI agent that investors took as confirmation that the buildout of AI computing capacity still has room to run. The rally was steep enough to push the Nasdaq 100's Relative Strength Index (RSI, a momentum gauge on which readings above 70 are usually read as overbought) to 81, even as the Dow Jones Industrial Average stalled at 52,500 — a sign the day's gains were concentrated in a handful of chip and AI-adjacent names rather than spread across the broader market. Crude oil moved opposite to what the day's geopolitical headlines might have implied. Houthi rebels claimed attacks on Riyadh, and flames and smoke were reported near the Saudi capital's airport — ordinarily the kind of supply-side shock that lifts oil on fears of disrupted output from the world's largest crude exporter. Instead, oil slipped, because traders focused on a second story: signs that Washington and Tehran are edging toward talks, after President Trump said he would "probably be open" to meeting Iran's president at the United Nations. The prospect of engagement with Iran raised the odds, in traders' eyes, of eased sanctions and more Iranian barrels eventually reaching the market, which outweighed the risk premium from the attack on Saudi Arabia. The dollar firmed as traders priced in more tightening from the Federal Reserve, a shift that showed up almost immediately in bank results: Huntington cut its outlook the same week the Fed hiked, flagged as a possible first crack in regional-bank net interest margins — the spread between what lenders earn on loans and pay on deposits, which narrows when rates rise faster than loan books reprice. The same cautious mood showed up in retail and housing: American Eagle held its full-year forecast steady and was sold off anyway, while Lennar's earnings miss added to concern that housing is weakening under higher rates. With the Nasdaq 100 already overbought, even in-line guidance was being read as a cue to take profits rather than add. Bitcoin extended its rebound, breaking above $85,000 for the first time in eight months as short sellers — who had bet on a decline — were forced to buy back positions to close out losses, a mechanic known as a short squeeze. The move carried through the session: bitcoin and ether rallied further as U.S. Treasury yields eased, and tech stocks moved with them, extending the same risk-on tone that lifted chipmakers. SoftBank added to the AI financing story separately, moving to sell more than $11 billion in bonds — up from an initial $10 billion term sheet — to fund its stake in OpenAI, underlining how much of the current AI buildout is being financed with debt. Elsewhere, Novo Nordisk shares sank after its chief executive admitted doubts about the company's drug pipeline, and Volkswagen and Porsche shares kept falling after a profit warning, with Porsche facing a possible additional 4,000 job cuts according to a Handelsblatt report — a reminder that outside chips and crypto, several large-cap names were still working through company-specific problems rather than riding the broader tape. Going into the next session, three things remained unresolved. First, whether the approaching Trump-Xi summit, ahead of which the U.S. and China have already agreed to open a dialogue on AI, produces anything concrete — a prospect that has kept Asian and European stocks rising in anticipation rather than in response to actual news. Second, whether the Iran diplomacy that pulled oil lower survives further attacks like the one on Riyadh; a breakdown would remove the offset that kept crude from spiking. Third, whether the Nasdaq 100's overbought RSI of 81, alongside a Dow stuck at 52,500, resolves through the rally broadening into the rest of the market or through a pullback in the chip names that carried it. The day's cross-currents showed up in Indy News's own Buy List 2026 model portfolio, which held €110,000 invested across 22 positions and closed at €117,795, a total return of +7.09% (+6.47% on price alone). MicroStrategy, whose treasury holds bitcoin, was the standout at +74.73%, benefiting directly from bitcoin's push through $85,000, while the portfolio's Novo Nordisk stake was down 14.56%, tracking the pipeline concerns raised by its own chief executive.