But while transport stocks have been buoyed by positive expectations about economic growth, Nathan doesn't actually believe that the economy is particularly strong.
"The world is convinced ... that the economy in the U.S. is improving," Nathan said. "I'm not so certain about that. I'd rather be a bit skeptical based on some of the price action that we've seen in the equity markets up here."
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Mike Khouw of Dash Financial agrees that economic optimism has made transport stocks vulnerable.
"FedEx and UPS are valued essentially based on a recovering economic growth story. These things are not overwhelmingly cheap at current levels," Khouw said. "There's probably more risk to the downside in the near term."
To make a bearish bet on transport stocks, Nathan recommends buying a put spread on the (IYT) ETF he referenced. But the key to this strategy is that economic data have to stay weak.
"This is a sector where I think, if we get mildly poor economic data, the market stays the way it is, I think this is the next sector to drop," Nathan said.
—By CNBC's Alex Rosenberg.