Lululemon is facing a growth inflection point — and it likely doesn't bode well for investors, Bernstein warned. Analyst Aneesha Sherman downgraded the fitness-wear stock to underperform from market perform. She also slashed her price target by $50 to $290, which implies a downside of 8.3% from where the stock closed Monday. "The expectations vs. reality gap has been our biggest concern this past year," she said in a note to clients Monday. "Now, with no more pent-up demand, a more cautious consumer outlook, and negative margin mix shifts, earnings growth will decelerate materially and we expect the multiple to follow." The stock was down 2.6% before the bell. It lost 18.2% in 2022, meaning it modestly outperformed the broader market. 2022 marked what Sherman called a reprieve for those hoping Lululemon could avoid its fate of tapering-off after years of growth, as pent-up demand buoyed the business. But Sherman said bullish expectations of 20% or greater top-line growth will get a "reality check." That's because pent-up demand is almost met, and North American consumers are becoming more cautious. The more promotional environment and the fact that Lululemon's new categories are not large enough to offset the softer core business have also played a role. She anticipates a deceleration to 13% revenue growth in the 2023 fiscal year, which she said is already reflected in management's medium-term targets but not yet investor expectations. Sherman said the company's focus on premium prices and little promotion drive "industry-leading margins." That said, Lululemon will feel structural headwinds from non-core category expansion, a slowdown in international stores and its need to lean more heavily on marketing and promotions. This changing environment should result in per-share earnings growth to slow from the 39% compound annual growth rate seen over the past five years to 33% for 2022, 12% for 2023 and somewhere in the mid-teen range after. That puts Lululemon below other high-growth sportswear companies and its pre-Covid growth, Sherman noted. The "growth reset," as she called it, could lead to further de-rating following 2023 guidance. Lululemon should also feel limited margin upside, she said. — CNBC's Michael Bloom contributed to this report.