Will AI Change the Stock Market? | The Distance Between Trending AI Stocks and Index Investing
Hello everyone. This is Nobi Nobi Asset.
Last time, we talked about fire insurance and earthquake insurance, and what to prepare for and to what extent.
This time, as promised, we will talk about the relationship between changes in industrial structure due to AI and the stock market.
◆ AI-related companies are at the center of the market
In recent years, AI development, as well as the semiconductors, cloud services, and major IT companies that support it, have been increasing their presence in the stock market. In fact, the top 10 holdings of global stocks (All Country) include large AI-related companies such as NVIDIA, Microsoft, Alphabet, Broadcom, and TSMC (as of May-June 2026).
Since it is a topic in the news almost every day, many people are likely wondering, “Will AI significantly change the stock market?”
◆ Industrial structures change with the times
However, it is not guaranteed that the “industries and companies currently in the spotlight” will remain the main players forever. As I mentioned before, in 1980, Japan accounted for about 15% of the global stock market, but that figure later dropped to around 6% (as of 2020). Depending on the era, “what is winning now” has always changed.
(Click here for the “Invest in the world and grow with the world” episode)
◆ Some compare it to past booms
The rising expectations for AI are sometimes compared to the IT bubble around 2000. During the IT bubble, there was a period between 2000 and 2002 when stock prices fell to about half of their highs.
(Click here for the “What to do if a crash happens?” episode)
However, no one can say for sure whether the current AI trend will follow the same path as the IT bubble or continue to grow with actual earnings. I would like to be just as cautious about labeling it a “bubble” as I would be about blindly believing that “this time is different.”
◆ If you hold index investments, you are naturally riding the AI wave too
If you hold an index fund like a global stock fund, you are effectively investing in AI-related companies naturally according to their market capitalization. If AI grows, you will receive some of the benefits. Conversely, you will also be affected by the concentration in AI-related sectors to that extent.
The high proportion of AI-related companies is also related to the issues of US concentration and the bias toward large technology companies that I discussed previously.
◆ If you are thinking of investing by focusing on AI
There are also ways to invest by focusing on AI-themed funds or individual stocks. However, the points of caution I discussed in the episode on theme-based funds—such as costs, the tendency to buy when they are popular, and the risks of concentration—apply just the same. If you do invest, one approach is to limit it to a very small portion of your total assets and keep the amount at a level where you can continue even if the price drops.
◆ Future results cannot be guaranteed
It is impossible to say for sure what kind of impact AI will have on industries and the stock market from here on out. This article is not intended to predict future market trends or recommend specific stocks or products.
◆ In my case
As of November 2026, when this article is being written, there is talk of Anthropic’s IPO, so it is a very hot topic.
As mentioned in the text, I don’t know if AI will go up or down, but the fundamental idea of index investing is that “no matter what happens, you will have moderate gains and losses in the short term, and you should be able to make a moderate profit in the long term (in theory, no guarantees).”
Let’s keep building it up calmly.
◆ Finally
Trending technologies often stir up the feeling of “not wanting to be left behind.” That is exactly when you should return to the question, “Why am I investing?” Next time, I will talk about whether it is profitable to use credit card points for investment, and the compatibility between point-earning activities and accumulation investment.
Look forward to it!