(FORTUNE Magazine) – Flip a chart of the Nasdaq upside down, and what does it look like? A stock chart of Anheuser-Busch, actually. So far this year Bud has risen on an astonishing 80% of the trading sessions in which the Nasdaq has slipped, notes Tom Gentile, chief market strategist at Optionetics, an educational company based in San Mateo, Calif., geared toward online options traders. To be more specific, Bud's 52-week low in March corresponded almost to the day with the Nasdaq's 52-week high. And in late May when the Nasdaq was dangerously near its low for this year, the beermaker posted a new high.

Bud's not the only one. A handful of stocks, including Boeing, Emerson Electric, and some consumer staples like PepsiCo, have been moving in an uncanny reverse-tandem with the Nasdaq this year. What's going on? "It's a rotation of funds," explains Skip Carpenter, an analyst at Donaldson Lufkin & Jenrette who follows Anheuser-Busch. "When people get concerned about tech valuations, you'll see them taking a more defensive posture and pouring money into consumer staples." This year there seems to be a particularly high correlation, perhaps due to skittish tech investors who have been greeting any shred of potentially negative news with two words: "Sell. Fast."

For people like Gentile, who designs options strategies and teaches investor seminars, this reverse-tandem effect has a very practical purpose: hedging volatile technology plays. Instead of buying bonds or "put" options to hedge a portfolio, his research has shown, it can be as effective to take positions in a consumer icon like Anheuser-Busch, which not only will give downside protection in case of a tech meltdown, but will also appreciate over time. So in a worst-case scenario, at least something will be headed in the right direction.

Though this inverse effect mostly can be chalked up to fund managers and institutional buyers shifting money around, individuals can also take advantage of the swings by owning a few staples to help hedge options plays or a tech-heavy portfolio. Now, we're not advocating that you go out and shield your massive Yahoo position with a couple of Boeing shares. "A correlation in the past doesn't mean it's going to hold in the future," warns financial planner John Wyckoff of Portland, Ore. Still, balancing more risky gambits is "why you own consumer staples like Anheuser-Busch or PepsiCo," says Carpenter. "They have high-quality brands, predictable earnings, and they're not going to tank." So if you think the Nasdaq is going to keep blowing off steam, these stocks may make sense. Of course, there's another reason to own the company that makes Tall Boys during a tech slide. Jokes Gentile: "When the markets are down, everyone's out drinking twice as much."

--Lee Clifford