While lululemon athletica  (LULU -0.52%) has exploded in popularity recently as a high-end retailer of women's fitness and yoga apparel, the market may expect more from the stock than it can deliver. Its sky-high valuation shows that the stock is priced to perfection, and while growth is strong for the company at the moment, being so dependent on a single fitness trend, such as yoga, is historically not without its perils. In this video, Motley Fool analyst Austin Smith tells us what the dangers can be for investors with a very pricey, trendy stock that is on the radar of a lot of competitors.