Because 10 stocks now make up nearly half the S&P 500 and a handful of banks and tech firms are coming to dominate fixed income too, true diversification no longer exists in public markets and can only be found in private markets, where the biggest companies like Anthropic, OpenAI, and SpaceX remain inaccessible to most investors.
Rowan argues extreme concentration in public stock and bond markets means real diversification now only exists in private markets, where the largest, fastest-growing companies live. ✦ AI generated
Marc Rowan · a16z Podcast · 2026-05-27 · original ↗
starts at this moment · 10:36
“I guess what did you see in Athene? And how do you sort of view the firm today?”
10 stocks right now in the US are nearly 50% of the S&P and they're all levered to the same trend... if you're an investor and you're looking for diversification, there's no place to get it other than private markets. Private markets are 80% of the action going on in the world.
verbatim transcript · starts at 10:36
10:36>> And finally we are diversification for public markets and this is the least understood portion >> of what we do. 10 stocks right now in the US are nearly 50% of the S&P and they're all levered to the same trend. >> Yep. >> So far that's been amazing. >> Yep. But we've levered most of the retirement system of the country. Yep. >> To 10 stocks. We can question in
10:59hindsight the wisdom of that if things go poorly. And so the same thing, by the way, is happening in the global fixed income market. >> Dominated historically by 10 large banks, it's about to be dominated by five large banks and five large tech companies. As much concentration as exists in the equity market, that's how much concentration is going to exist in the fixed income market. And so if
11:22you're an investor and you're looking for diversification, there's no place to get it other than private markets. Private markets are 80% of the action going on in the world. >> And if you think about what's going on, great companies, Enthropic, Open AI, SpaceX, Cognition, Cursor, >> and on and on and on. Every one of those companies is private, multiple trillion dollars >> of value and yet most investors have
11:53zero exposure to them. >> We we're going to see the same thing happen with industrial companies. Lots of industrial companies are just going to decide to stay private longer for all the reasons we know. And so when I think about the business today, it is serving those fundamental goods. But it is also built on trends. The trends are the world is getting older. People have not adequately saved for retirement. There's
12:18this massive retirement income gap that's driving our business forward. >> They need income. Well, at the same time, corporations are borrowing money like every dollar since the invention of fire >> to build infrastructure, to build energy, to do energy transmission, to do next-gen manufacturing, to do AI, to do defense, to do data centers, and it's all happening at once. And so mostly investment grade borrowers, large companies against modern trends matching
- ·10 stocks are nearly 50% of the S&P 500
- ·All levered to the same trend
- ·Banks and tech firms dominate fixed income too
- ·Private markets hold 80% of global economic action
- ·Biggest private firms (Anthropic, OpenAI, SpaceX) stay inaccessible
- ·Real diversification now exists only in private markets