AI Semiconductor Rally Continues; Memory Stocks Most Expensive Since 2021 Despite Scorching Performance

The AI semiconductor rally has entered a phase where price performance is outpacing fundamental valuation expansion. Memory chip stocks like Micron (MU) and broader semiconductor names are now trading at elevated multiples relative to historical norms, yet their stock prices continue to push higher. This divergence, rising stock prices amid compressed valuations, typically signals crowded crowded trades where momentumThe empirical fact that winners keep winning over the medium term. and passive flows are driving prices more than earnings growth. Nvidia's breakthrough past $5.5 trillion market cap is both a testament to AI infrastructure demand and a red flag for conviction traders.

The narrative around AI capex remains contested. Sell-side strategists are warning of "peak capex" risk, suggesting that the historic levels of spending on data centers, GPUs, and training infrastructure may not sustain forever. Meta's $21 billion commitment to CoreWeave for inference capacity is being scrutinized: is this expansion or consolidation of already-announced budgets? Cisco's recent earnings call hinted at sustained networking demand for AI buildout (switches, optics, routing), but the commentary lacked the exuberance of earlier quarters. Broadcom (AVGO) could become a constraint if chipmakers cannot source critical passive components.

Institutional positioning is mixed. Some passive index trackers are overweighting AI mega-caps simply due to market-cap indexing; Palantir (PLTR) and Super Micro (SMCI) have attracted retail attention but remain controversial for governance and accounting. Raymond James analysts flagged AMD and Arista (ANET) as potential next-gen beneficiaries if customers diversify away from Nvidia monoculture, but adoption timelines remain uncertain.

The bearish case hinges on capex deceleration or disappointing ROI. If major cloud providers (AWS, Azure, Google Cloud) report underwhelming returns on AI infrastructure spending, capex budgets could contract sharply, pressuring Nvidia, AMD, and supporting foundries. Nvidia's China export restrictions (if reversed) could spark margin competition as Beijing-based chipmakers gain parity in supply chains.