How Much AI Do You Really Own?
Follow the whole story: every piece in this series is on our AI storyline page.
What Does Everyone Already Know?
The Nasdaq 100 closed Monday more than 10% below its Oct 6 record, and was still about 9% below it at Wednesday’s close. Most investors know their AI exposure the way they know their own holdings: a line for Nvidia, a line for Microsoft, a line for Alphabet. Add those up, and that’s the number.
The market doesn’t count that way. When AI stocks fall, everything tied to AI spending falls together, whichever account it sits in and whatever the fund is called.
| A $5M portfolio | Value | AI share | AI exposure |
|---|---|---|---|
| 1. AI stocks you bought (Nvidia, Microsoft, Alphabet, Amazon, Meta) | $1.0M | 100% | $1.0M |
| 2. S&P 500 index fund | $2.0M | about 30% | $600K |
| 3. Suppliers and power (servers, chips, utilities) | $400K | about 75% | $300K |
| Other stocks | $400K | 0% | $0 |
| Bonds and cash | $1.2M | 0% | $0 |
| Total | $5.0M | $1.9M (38%) |
The owner thinks AI is 20% of the portfolio. Counted the market’s way, it’s 38%.
In a 2022-style drop, when AI leaders lost about half their value, that $1.9 million would lose about $950,000, or 19% of the whole portfolio, from the AI theme alone. In a 2000-style drop of about 75%, the loss would be about $1.4 million.
See more lines: how we counted the index fund and the suppliers
The example portfolio is illustrative. Index-fund look-through: at Wednesday’s prices, Nvidia, Microsoft, Alphabet, Amazon, Meta and Broadcom were worth about $18.5 trillion together; counting them and the other big AI chip, server, software and power names (AMD, Micron, Oracle, Palantir, Dell, Intel, Marvell, Constellation, Vistra), we estimate roughly 30% of the index. The widely quoted “Magnificent Seven” share, which also counts Apple and Tesla, was about 34–36% of the index this year. The 75% for suppliers and power is our assumption that most of that sleeve is names like Dell, Vistra and Constellation, which we treat as tied to AI data-center demand. Scenario losses: −50% (2022 case) and −75% (2000 case) apply to the whole AI exposure, consistent with our concentration piece.
Why Does An Index Fund Hide So Much AI?
Because the index is weighted by value, and the biggest values are AI. The ten largest companies are now close to 40% of the S&P 500, a share not seen since the 1960s. So a fund sold as “the whole market” gives you about 30 cents of AI for every dollar, by our count. If you own a Nasdaq 100 fund, it’s more.
Here’s the surprise for most owners: when AI stocks fell this past month, the index fund didn’t offset the direct holdings. It slipped too (the SPDR S&P 500 ETF was down about 0.4%), because it holds them. Alphabet is down 16% in a month, Meta 13% and Nvidia 14%.
What Counts As An Indirect AI Stock?
Anything whose growth depends on the AI giants’ spending. The four cloud giants alone spent about $202 billion on capital projects in the last quarter. That money buys servers, chips, memory and electricity. So the suppliers move with the theme: Dell is down 34% in a month, Micron 26% and Marvell 41%.
Power is the subtler case. Constellation Energy and Vistra are down 5% and 14% this month, after sharp drops on Wednesday; they are 35% and 37% below their 52-week highs, and down 32% and 35% over 12 months. They don’t move tick for tick with Nvidia, but they rest on the same bet: that data centers keep needing more electricity. If the spending slows, they’ll find out together.
This is the part most portfolios never add up: the same theme sits in your stock account, your index fund, your 401(k) and the “safe” utility you bought for income. Our example family owns nearly twice the AI it thought. A Trefis partner firm can count your AI exposure across every account.
What Should You Do This Week?
Three steps, in order. This is education about how to think about exposure, not personal advice; the right numbers depend on your taxes, age and goals.
1. Count it. List every account. For each stock, decide whether its growth depends on AI spending. For each fund, look up its top holdings and their weights; the fund’s own fact sheet lists them. Add the three numbers: direct, look-through and indirect. Divide by your total.
2. Set a cap. Pick the most you’d hold in any one theme, counted this way. A common way to set it: decide the most you could lose on the theme without changing your plan, then divide by the theme’s worst drop. If our example family could live with losing $625,000 in a 2022-style drop, its cap is about 25%, or $1.25 million. Sized for a 2000-style drop, the same $1.25 million would lose about $940,000.
3. Set a band, and use it. With a 25% target, rebalance when the count goes above 30% or below 20%. Our example is at 38%, so it would trim about $650,000 back toward 25%. Trim the direct holdings first, since the index fund is already diversified, and do it in stages. Losses from this year’s selloff can help: Oracle is down 50% over 12 months and CoreWeave 58%, and in a taxable account, realized losses can offset gains from trimming a winner (mind the 30-day wash-sale rule). The tax-aware tools, from staged sales to exchange funds, are in our concentration piece, the first question listed at the end.
The band works in both directions. If AI stocks fall further and your count drops below 20%, the same rule tells you to buy, at prices you’ve already decided are fair.
What’s The Bigger Idea?
Exposure hides in plain sight. Risk isn’t the number of names you own; it’s the number of bets. Five AI stocks, an index fund and two utilities can be one bet. The market adds up your exposure for you on the day the theme turns, and it does so at the worst prices. Adding it up yourself first is free.
Count your AI in three numbers: what you bought, what’s inside your funds, and what supplies the build-out. On our $5 million example, a portfolio that looked 20% AI was 38%, enough to lose about $950,000 in a 2022-style drop. Set a cap, set a band, and trim or buy when the count crosses it.
What Should You Ask Next?
- What would a 2022-style drop cost an AI-heavy portfolio, and how do you cut it without a big tax bill?
- Is this 2000 or 2018? Three numbers that tell an AI bubble from a correction
- Google at $289: buy now, or get paid to wait for $220?
We’re tracking the AI selloff piece by piece, with the numbers that matter for your money. Follow the story, and tell us what you’d want counted next.
How Much AI Is In Your Portfolio?
Corrections test concentration, not conviction. If you have $1 million or more invested, see how exposed your portfolio is to the AI trade in a free 15-minute call with a Trefis partner firm.
For questions about this article or underlying research, email help@trefis.com.