Lemonade (LMND -0.55%) has been a popular stock for growth investors ever since it went public in 2020. The insurance start-up has touted its asset-light artificial intelligence (AI) approach to insurance, hoping to disrupt the legacy players with modern digital tools and lower rates for things like renters and car insurance. It now has 2 million active customers in less than nine years after its founding in 2015, making it one of the fastest-growing companies of the last decade.But its stock price hasn't r ...