"When VF Corp makes an acquisition, it can almost automatically assume much higher sales and margins over time," Saad wrote, crediting VF's ability to operate more effectively and gain pricing power. For example, VF manufactures as much as 30 percent of its products in-house.
Read MoreWe 'let down our guest a little': Lululemon CEO
Who Saad said he thinks VF could buy and why:
• Lululemon would be a good fit for both companies because "VF Corp has in spades what Lululemon lacks: aspirational lifestyle brand-building capabilities, deep-rooted product innovation platforms, and a best-in-class, scaled supply chain."
Read MoreOn your mark! New rival in sports apparel race
• Despite falling behind Nike and Adidas, Puma remains the third-largest brand in the athletic space and has potential to expand geographically and into new categories.
• Lands' End could be used by the company to enter the mid-priced market. Although the brand, which completed its spinoff from Sears last month, was undermanaged and underinvested in for years, its sailing heritage nonetheless gives it a level of authenticity.