Diversifying your portfolio isn't as simple as it once was.

The artificial-intelligence boom is lifting many boats, including sectors and in regions typically driven by different fundamentals. AI-related stocks are the main driver behind many broad indexes. And even the traditional hedge to equities -- the bond market -- is moving with stocks.

What can an investor do? Dive deep into your current holdings to discover what you are exposed to, experts say. Then tweak your investments by finding assets that are less correlated with each other to spread the risk.

Here's how.

Take stock

Get under the hood of your investments in your 401(k) and other investment accounts. What funds do you hold? What do those funds include? And what's driving their returns?

"You really have to do the X-ray and know how much they overlap and how much you are exposed to the more volatile areas of the AI trade," said Patrick Huey, owner of Victory Independent Planning.

Even traditionally diverse index funds need a second look.

Many are designed to track the performance of a broad index, such as the S&P 500. But the index is capitalization weighted, meaning larger companies influence the index's performance more. Lately, those large companies are AI ones.

That is all well and good when those stocks are booming. But if -- and when -- they lead to a selloff, that leaves your portfolio overexposed to the AI trade.

"In 401ks, you're kind of forced into these index funds and so you're gonna take it on the chin if the market goes down," said Monica Dwyer, a senior vice president at Harvest Financial Advisors.

How to diversify with U.S. stocks

So let's diversify -- starting with U.S. stocks.

One big factor to consider is how directly exposed a stock or sector is to the AI trade. While AI is buoying the fortunes of traditionally less correlated sectors like technology, utilities and real estate, the boost isn't uniform.

AI chip companies and memory chip manufacturers have the most direct exposure, whereas many areas of real estate -- such as retail or multifamily -- have much less.

Power companies, the energy demand from data centers, may fall in the middle.

"Utilities probably tend to become more correlated with technology and AI than we used to think," said Laura Mattia, senior vice president at Wealth Enhancement.

Then there are sectors like healthcare. While AI may eventually improve healthcare services or disease research, healthcare demand is largely driven by an aging population, a trend that continues to grow -- with or without AI.

And if you want a large-cap index fund, "focus more on an equal-weighted one," Mattia said.

Look for mutual funds or exchange-traded funds like Invesco S&P 500 Revenue ETF that weights companies in the S&P 500 by revenue or Invesco S&P 500 Equal Weight ETF that gives each company the exact same weighting.

Go international

Investing in stocks abroad won't automatically diversify your portfolio now. U.S. equities make up roughly half of the global market, according to FactSet, and AI remains a big driver in overseas indexes.

So examine what your international holdings actually are. If you find too much AI exposure, maybe move away from those large-cap international stocks. Consider small-cap internationals instead.

"It's an interesting asset class that has done very well over the recent year or two," Mattia said. "They're more influenced by local behavior as opposed to the global economy."

Fix your fixed income

Don't forget to pore over your less risky assets like bonds.

"Historically you look for bonds to zig while stocks are zagging, and the reality is they're very highly correlated recently," said Catherine Valega, a certified financial planner at Green Bee Advisory.

Instead, Valega is turning to stable short-term liquid alternatives such as money-market funds, U.S. Treasury bills and certificates of deposit, or CDs, to fill out the conservative portion of her clients' portfolios.

"CDs are FDIC insured and Treasury bills are backed by the full faith and credit of the U.S. government, so why would I take a credit risk?" Valega said.

For corporate bonds, check out reinsurance or catastrophic bonds, which are influenced by natural disasters -- and not larger economic trends.

"A tsunami in Asia has nothing to do with what the Federal Reserve decides at their next FOMC meeting," Mattia said, "so there it's just a different source of risk."

Think outside the box

Maybe it's time for some tried-and-true alternative assets -- like commodities and precious metals. Take gold, for example.

"It has almost zero correlation to the U.S. stock market," said Matthew McKay, director of investments at Briaud Financial Advisors. "It has been a bit more correlated this past year but overall it's a pretty noncorrelated asset."

As for energy commodities, consider this: When stocks went gangbusters in recent years, energy commodities "blew it out of the water when you compare it," McKay said.

If your 401(k) doesn't offer a commodity fund, try a precious metals equity fund, McKay said.

"When gold's performing well, gold-mining stocks are like double, triple that type of performance," he said, "so it's a good diversifier from that perspective."

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