NVDA, AI chipmakers lead S&P 500 as Cerebras IPO pops 89 percent

The S&P 500 closed higher on May 15 as markets absorbed a wave of AI infrastructure momentumThe empirical fact that winners keep winning over the medium term., with the Nasdaq Composite outperforming amid broad strength in semiconductor and mega-cap technology names. The session reflected sustained institutional appetite for artificial intelligence plays as geopolitical risks softened following the Trump-Xi summit in Beijing, where NVIDIA CEO Jensen Huang attended alongside other tech and defense leaders. Volatility declined as risk sentiment turned constructively risk-on, though breadth concerns persist given the concentration of gains in a narrow set of mega-cap AI winners.

The semiconductor and technology sectors dominated gains, with Advanced Micro Devices, Broadcom, and NVIDIA all rallying on AI infrastructure spending narratives. Within the broader market, the "Magnificent Seven" cluster of mega-caps (NVDA, MSFT, GOOGL, META, AMZN, AAPL, TSLA) now accounts for 38 percent or more of the S&P 500 market cap, with NVIDIA alone representing approximately $5.5 trillion in valuation. Alphabet added significant ground on breakthrough AI announcements including Gemini models and memory compression technology, having gained $1.5 trillion in market value over just six weeks. Energy and defensive consumer stocks lagged as bond yields rose on persistent inflationThe rate at which prices rise across an economy. concerns, with treasuries sliding on higher oil prices threatening to keep rates elevated for longer.

Cerebras Systems emerged as the day's dominant single-stock story, surging 89 percent above its $24 IPOInitial Public Offering - a company's first public sale of stock. price on its first day of trading, raising $5.55 billion in what marks the year's largest technology IPO. The blowout opening validated institutional conviction in pure-play AI semiconductor specialists beyond NVIDIA's monopoly. Solana-based tokenized stocks approached $400 million in assets under management, signaling retail on-chain equity participation accelerating alongside traditional listing euphoria. Options activity across the Magnificent Seven showed gammaThe rate of change of delta - the option's curvature. positioning near record levels, with over $249 million in single-leg call premiums traded on May 13, amplifying upside momentumThe empirical fact that winners keep winning over the medium term..

The US dollar strengthened alongside higher treasury yields as copper extended its retreat from record highs, reflecting inflationThe rate at which prices rise across an economy. angst and a stronger greenback making commodities more expensive for overseas buyers. Crude oil prices remained pressured yet supported by geopolitical supply concerns, while gold held steady. The H200 chip approval for 10 Chinese companies signaled a subtle policy pivot on US-China tech restrictions, underpinning sentiment that trade tensions may soften further as Trump and Xi pursue bilateral talks. Bitcoin and tokenized assets participated in the risk-on tone, though specific close prices were not reported in today's data.

After-hours earnings and corporate actions were limited in the reporting window, with attention focused on the Cerebras IPOInitial Public Offering - a company's first public sale of stock. pop continuing to reverberate through semiconductor and AI infrastructure plays. Market positioning suggests Friday's open will hinge on overnight Treasury moves and any further China trade signals, with tech leadership likely to persist if the positive bilateral summit tone holds. InflationThe rate at which prices rise across an economy. data and Federal Reserve commentary remain key overnight catalysts that could shift the durationBond price sensitivity to interest rate changes. and breadth of the AI rally beyond mega-caps.