(Click for video linked to a searchable transcript of this Mad Money segment)

In expectations of a sell-off, Cramer suggests putting together a shopping list of stocks to buy on the way down.

"And I want you to put F5 Networks right at the top of your list," he said.

Largely the Mad Money host believes the stock is cheap and in the event of a sell-off he says "it just gets cheaper."

Of course, every cheap stock is cheap for a reason. And in the case of F5, "it's mostly because the company missed numbers in a big way during the spring," he said.

Although a big miss is hardly a reason to buy it may also not be a reason for the stock to slide as much as it did. Therefore, not only could the stock be oversold, also sentiment may be too negative.

And when that happens, pros often miss new bullish catalysts that can ultimately drive shares higher. In the case of F5, Cramer thinks the Street is missing two big catalysts.

1. Turnaround story

"As products get older, their sales tend to decline," Cramer explained. To that rule F5 is no exception. "In its most recent quarter, F5 posted a 10% year over year decline in product revenues, but that's because it was right at the trough of its key product cycle."

However, in this sector when companies come out with new and significantly improved versions of their products sales tend to surge.

And in the case of F5, "The company now has its biggest product line refresh in four years. I think when those new products start hitting the market, F5 should return to growth."

2. Too cheap

"Right now, F5 is sitting on a billion dollars of net cash on its balance sheet, which works out to $16 of cash per share. And the stock is selling for just 17.3 times next year's earnings estimates, but that multiple falls to less than 15 times earnings when you back out the cash," Cramer explained.

"Now consider the historical context," Cramer added. "Since 2007, on average, F5 has sold for 24 times earnings. If you gave the stock that multiple right now, it would be trading at $122, or more than 38% higher."

In any market, Cramer would consider these catalysts compelling reasons to buy. However, he sees something else.

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Because F5 is currently out of favor, in the event of a bigger sell-off, Cramer thinks the stock will be one of the first to go down.

And that will make it even cheaper!

"With the threat of a showdown in DC threatening markets, I always find it's important to remember that when stocks go down, they get cheaper. They become more, not less, attractive. Selloffs like this one create opportunities. And I think F5 presents an absolutely terrific opportunity."

Call Cramer: 1-800-743-CNBC

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