Charles Stanley remains a buyer of JD Sports Fashion after the outfitter of choice for trendy, sporty teenagers posted a 1.7% rise in like for like sales growth in the period from 1 February to 30 May.The broker thinks the company's strong performance recently has not been matched by its share price, which has more than doubled in the past half year.With a price-earnings ratio of 5.5, the stock is just too cheap, Charles Stanley says.It points to JD Sports', "sustained trading momentum, consistent delivery of profit surprises over the past few years, and what we see as a differentiated customer proposition that is poised to continue delivering future profit growth."The broker has a 471p target price on the firm.