"You can see again how well-defined the channel is," Worth said. "It responds beautifully over and over and over, and when you overshoot the top, you have the tendency to mean-revert. And we're looking for a 10-percent decline back to, or a little bit below, the middle of the range."
But if the outperformance looks overextended on the chart, perhaps it looks even more overextended on a fundamental basis. Looking at six names in the sector—Kraft, General Mills, Procter & Gamble, Campbell Soup, Coca-Cola and Costco—Worth notes that their average price-to-earnings ratio is 21.5, but their earnings growth over the last year is an average of 0 percent.
That tells Worth that people are buying shares of these companies not because the businesses are in good shape but because they feel compelled to buy something and would prefer to purchase stocks that are on the defensive side.
"This is a fear-based kind of a behavior, and it comes to an end more often than not," Worth said.
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"I just don't know how anybody would want to potentially chase this trade," agreed Michael Khouw of Dash Financial. " Where do you think these things are honestly going to go?"
So to make a bearish bet on the Consumer Staples ETF, Khouw recommends buying the September 44-strike put for $1.15. This trade will make money as long as the ETF is below $42.85 at September expiration.