With Audio Commentary: The Light and Shadow of the Semiconductor Bubble—Why Individual Investors Struggle to Win Easily in Individual Stock Trading

Hello. I am your reporter, Sanaichi.

Today, I will be reporting on the recent frenzy surrounding semiconductor stocks and the reality that individual investors face behind the scenes. Using AI information, I have created an audio commentary podcast on the free version of Gemini notebook. If you are busy, you can listen for free at 1.25x or 1.5x speed.

As many of you know, Nikkei 225 futures have a very high correlation with the Nikkei Stock Average. Since Nikkei 225 futures indicate the expected future price of the actual assets, they move in tandem with almost the same price action. In a market environment driven by AI and semiconductors like the current one, the Nikkei Semiconductor Stock Index also moves with a very strong correlation.

On August 5, 2026, a particularly noteworthy point in the market that day was the structure in which individual AI and semiconductor-related stocks were strongly driving the entire Nikkei average to record-breaking, significant consecutive gains. The impact of major stocks like Advantest and SoftBank Group on the entire market is significant, and the SOX index in the US market and strong earnings reports are directly spilling over into Japanese stocks.

However, for investment beginners who have recently started trading individual stocks like Advantest, the price action has been harsh. Looking at 3-month or 6-month charts, they are consolidating in high price ranges, and the shorter the timeframe, the more volatile the price movements become. The reality is that individual investors are easily forced into cutting their losses. Even from the perspective of a professional reporter or writer, there is no absolute need to take risks in short-term trading with high uncertainty.

For investment beginners who really want to make a profit from semiconductor stocks or want to benefit from the growth of the semiconductor market, a more realistic option is to look for investment trusts, index funds, or ETFs linked to the Nikkei Semiconductor Stock Index, which can reduce the risk of being swayed by the minute price movements and noise of individual stocks.

The Nikkei Semiconductor Stock Index is composed of 30 major semiconductor-related stocks listed on the Tokyo Stock Exchange, and it has the characteristic of being top-heavy, with top stocks such as Kioxia Holdings, Tokyo Electron, Advantest, Disco, and Renesas Electronics accounting for a large portion of the weight.

As for specific products, if you want to trade in real-time, you can consider TSE-listed ETFs such as the NEXT FUNDS Nikkei Semiconductor Stock Index Linked Exchange Traded Fund or the Listed Index Fund Nikkei Semiconductor Stock, which are eligible for the NISA growth investment quota. Also, for non-listed investment trusts that emphasize automatic accumulation and compound interest reinvestment, you can utilize products like the Nomura Index Fund Nikkei Semiconductor Stock.

The Nikkei Semiconductor Stock Index is also called the Japanese version of the SOX index, but if you wish to invest in the US market, the following products are presented for comparison.

Global X Semiconductor ETF (2243): A TSE-listed ETF linked to 30 major US-listed companies (SOX Index).

Nissay SOX Index Index Fund: An investment trust linked to the SOX Index.

As reference information, I will introduce a list of all 30 stocks that make up the Nikkei Semiconductor Stock Index, in descending order of market capitalization weight (as of the end of April 2026).

This index is composed of major semiconductor-related stocks listed on the Tokyo Stock Exchange, and regular rebalancing is conducted once a year (at the end of November).

List of all 30 stocks in the Nikkei Semiconductor Stock Index (as of the end of April 2026)

Kioxia Holdings (23.3%)

Tokyo Electron (12.4%)

Advantest (11.7%)

Disco (9.2%)

Renesas Electronics (6.9%)

JX Metals (5.1%)

Shin-Etsu Chemical (5.0%)

Lasertec (4.6%)

HOYA (3.7%)

Sony Group (2.3%)

SCREEN Holdings (2.2%)

KOKUSAI ELECTRIC (1.7%)

Rohm (1.6%)

Tokyo Ohka Kogyo (1.3%)

Nissan Chemical (1.1%)

SUMCO (1.00%)

Tokyo Seimitsu (0.83%)

Rorze (0.74%)

Taiyo Holdings (0.65%)

Sumitomo Bakelite (0.59%)

ULVAC (0.55%)

Macnica Holdings (0.55%)

Dexerials (0.50%)

ADEKA (0.47%)

Ferrotec Holdings (0.41%)

Socionext (0.38%)

Tokuyama (0.33%)

Nippon Kayaku (0.32%)

Kaga Electronics (0.25%)

TOWA (0.25%)

Index Characteristics and Recent Trends

Top-Heavy Concentration: The top 3 to 5 stocks (such as Kioxia, Tokyo Electron, Advantest, etc.) can account for over 50% of the index's total weight, creating a structure highly susceptible to the influence of specific stocks.

Stock Rebalancing: In the most recent (November 2025) periodic rebalancing, Kioxia Holdings and JX Metals were newly adopted, while Tokyo Electron Device and Sanken Electric were removed. Additionally, JSR was removed in May 2024 due to a TOB.

Sector Breakdown: It is mainly classified into four categories: semiconductor manufacturers, semiconductor trading companies, semiconductor manufacturing equipment manufacturers, and semiconductor material manufacturers.

By utilizing investment trusts or ETFs that track the Nikkei Semiconductor Stock Index, which encompasses these 30 stocks, it is possible to enjoy the growth of the entire Japanese semiconductor industry while suppressing the risk of being swayed by the intense price fluctuations of individual stocks.

*This article does not recommend the buying or selling of any specific stocks. Please make investment decisions at your own risk.

▼ Recommended articles and information to read together