Billionaires Are Loading Up on Index Funds While Retail Investors Chase Crypto. Here's Which Side I'd Bet on for 2035.​

The richest investors don't need to hunt for the next moonshot all of the time. Some of the most successful billionaires, like Ray Dalio, the founder of Bridgewater Associates, are currently piling capital into exchange-traded funds (ETFs) that track the market, precisely while retail investors keep chasing speculative crypto bets that torched a lot of their cash in 2024 and 2025. Less-speculative crypto assets, like Bitcoin (CRYPTO: BTC) and Ethereum (CRYPTO: ETH), haven't necessarily performed that well either relative to the rest of the market recently.

So these different investor camps can't both be right about which assets are going to be worth a lot more by 2035. Let's sort out which approach is more deserving of your capital.

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The slow road is a good one if you can afford to be patient

When billionaires buy market-tracking instruments like the SPDR S&P 500 ETF Trust (NYSEMKT: SPY), they obviously aren't looking to outperform the market. After all, they aren't speculators reaching for lottery tickets.

Still, their conservative bets have tended to pay off. During the past century, the S&P 500 has produced annual average gains of roughly 10% for those who reinvested their dividends; during the more recent 10-year stretch, its returns have run near 15%.

For anyone who doesn't yet have some exposure to a broad index fund, it's thus probably a good idea to buy some. Owning an asset that delivers exposure to 500 of the largest U.S. companies insulates you against the failure of any single business or narrative, and it can anchor your portfolio with at least some growth at the same time.

Crypto offers many paths, some of which are dead ends

Crypto deserves a place in most portfolios, too, but it's simply a much smaller one than index funds warrant. Plus, many investors tend to gravitate toward the sector's least reputable assets instead of the ones most likely to make them richer over time -- and that's a mistake you will rarely see the billionaires making.

In 2025, the meme coin market cap crashed, with 90% of the top meme coins losing a vast amount of their value. Retail investors chasing those cryptos got burned, and yet they keep going back to get burned again even when there are better options available.

For instance, Bitcoin is a finite-supply asset that also tends to function as an index-like bet on the crypto sector as a whole. Beyond that, Ethereum plays a parallel role for the decentralized finance (DeFi) segment of crypto, as it hosts about $53 billion of the $92 billion in total value locked (TVL) across all DeFi protocols.

Both these assets belong in a well-diversified crypto portfolio, which you should only build once you have a traditional portfolio holding plenty of index fund shares.

For growth, I am betting that at least Bitcoin and also probably Ethereum will outperform the broader market by 2035. They're still both gaining adoption as assets.

But, in practice, I will still be allocating a lot to index funds, too, as their diversification potential is too good to pass up.

Alex Carchidi has positions in Bitcoin, Ethereum, and SPDR S&P 500 ETF Trust. The Motley Fool has positions in and recommends Bitcoin and Ethereum. The Motley Fool has a disclosure policy.