For years, YouTube star Hank Green has adhered to the same simple investing wisdom promoted by legends like Warren Buffett: Put your money in an S&P 500 index fund and leave it alone.
That advice has paid off for millions of investors: This year alone, the index is up about 16%, and has gained an average of more than 20% over the past three years and about 14.6% over the past two decades. In most cases, investors who try to pick individual stocks like Tesla or Meta are easy to beat.
But as Wall Street worries about a possible AI-driven bubble – with voices from “Big Short” investor Michael Burry to economist Mohamed El-Erian sounding the alarm – Green isn't waiting to see what happens. He's already thinking about how much of his own wealth is tied to Big Tech.
A key reason: The S&P 500 is more concentrated than ever. The top 10 companies – including Nvidia, Apple, Microsoft, Amazon, Google and Meta – make up almost 40% of the entire index. And almost everyone is investing billions in AI.
“I feel like my money is being displayed more than I would like,” Green said in a video that has been viewed over 1.6 million times. “Because I have a lot of my money in the S&P 500, I feel like I'm betting on a big AI future now. And that's not a future that I definitely don't think will happen.”
So Green is hedging his bets. He's taking 25% of the money he previously invested in S&P 500 index funds – a significant chunk for a self-made millionaire – and moving it into a more diversified investment group, including:
- S&P 500 Value Index Fundsthat target companies with lower valuations and less AI-driven hype.
- Mid-cap stockswhich he believes could be beneficial if smaller companies benefit more from AI's productivity improvements.
- International index fundswhich provides exposure outside of the tech-heavy US market.
Green's thesis is simple: Even if AI transforms the economy, the biggest winners ultimately may not be the mega-cap companies that develop the models.
“I think that these giant companies that provide the AI models will actually compete among themselves for these customers, in part through price competition,” Green said. “And that could mean that the value for small companies will be greater than the value for the big AI companies. Who knows? I just think that could happen.”
And if his concerns are overblown? He agrees with that too.
“If I’m wrong, 75% of my money is still in the safe place everyone says it should be, which is the S&P 500.”
The YouTuber’s message to his Generation Z and Generation Alpha viewers: The stock market is not a “Ponzi scheme”
According to TIAA, Generation Z lags behind other generations in financial literacy, from saving and investing to understanding risk. Additionally, one in four admit they are unsure of their financial knowledge and skills – a stark admission considering one in seven Gen Z credit card users have maxed out their credit card and many young people have thousands in student loan debt.
As a self-described “successful middle-aged person at age 45,” Green said he tries to illustrate what thoughtful, long-term decision making actually looks like. And part of that effort is to clear up a big misconception that some of his listeners share:
“I get comments like this from people saying, I can’t believe you’re participating in this Ponzi scheme,” Green said Assets. “I want to upset these people because I don't believe the stock market is a Ponzi scheme. I do think it's overvalued right now, but I think it's tied to the real value that's really being created in the world.”
His broader point: Investing isn't about sentiment or simply putting money into the hot stock of the week; Rather, it is something that needs to be seriously explored.
“A lot of people think that investing is like opening a Robinhood account and buying Tesla,” Green added. “And I'm like, 'No, you need to get a Fidelity account and buy a low-cost index fund for everyone and just keep it in your 401K and let the people who manage it run it' — which a lot of people do, which is fine.”
His younger viewers are paying attention. One popular comment summed it up: “As a young person who is at the point in my life where I'm starting to think about investing, I really appreciate you laying out your logic and making a lot of disclaimers instead of telling me to buy exactly what you're buying, buying, buying.” The comment has already garnered more than 4,700 likes.
Financial advisors agree: portfolio diversification is key
Although Green doesn't have a finance background, experts in the world of investing largely agree with his reasoning: A diversified portfolio is the way to go – especially if you're worried about an AI bubble.
“Unlike many dot-com companies, today's tech giants generally have significant revenue, cash reserves and established business models that go beyond just AI,” said certified financial planner Bo Hanson, host of The Money Guy Showhe said in a video analyzing Green's opinion.
“Nonetheless, concentration risk remains a legitimate concern for investors seeking diversification. However, for this very reason, we advise against allocating all investments exclusively to the S&P 500, particularly if you have a shorter investment horizon.”
Hanson added that smart investors spread their money across different asset classes, including small caps, international investments and bonds, to reduce portfolio volatility and make money
more consistent returns in different market environments.
That sentiment is echoed by Doug Ornstein, principal at TIAA Wealth Management, who said it's important to recognize that not every investment has to be growth-oriented.
“Especially as you get older, having guaranteed income streams becomes crucial. Products like annuities can provide reliable payments regardless of market fluctuations, creating a foundation for financial security,” said Ornstein Assets. “Think of it like creating a floor under your portfolio – a floor that market volatility can’t touch.”