Advantest, a key player in the chip-testing equipment sector and a supplier to Nvidia, saw its shares surge by 18% over three days, culminating in a 1.5% rise on Thursday. This rally was fueled by the company's robust profit outlook. Advantest, with a market capitalization exceeding $83 billion ($12.9 trillion yen), is a significant component of the Nikkei 225, accounting for approximately $5.26 billion of the index's total weighting.
Despite this strong performance, the company is facing a looming threat of a Nikkei weighting cut, which could trigger significant selling pressure from passive funds. As of October, the Nikkei will replace a stock based on its free-float adjusted market capitalization, a methodology shift that could disproportionately impact Advantest. Investors closely watch such adjustments as they dictate the allocation of capital by index-tracking funds.
Analysts have noted a "typical trend in recent sessions" where AI-related shares, such as Advantest, have surged, while value shares like banks have been sold off. For instance, Toyota Motor fell 1.71% and Nomura Research Institute lost 6% on Thursday. This indicates a divergence in market sentiment between growth-oriented tech stocks and more traditional sectors. Advantest's recent gains follow a period of volatility; earlier in the week, it plunged 9.1% on Monday, contributing significantly to the Nikkei's slide to a three-week low due to a broader tech sell-off.
The potential Nikkei rebalancing could erase some of Advantest's recent gains, creating headwinds for the stock. This situation highlights the dual impact of company-specific performance and broader index mechanics on stock valuations, especially for heavily weighted components. Any significant decrease in Advantest's weighting would necessitate portfolio adjustments by passive funds tracking the Nikkei, potentially leading to increased selling volume.
