Shares of Stitch Fix (NASDAQ: SFIX) jumped 9.3% this week compared to where they closed last Friday, according to data from S&P Global Market Intelligence. Stitch Fix stock is now up over 110% since the run higher began, though the shares remain 66% below their 52-week highs. Stitch Fix uses proprietary data science and algorithms to match personal data entered by customers and the merchandise offered by merchants to create a personalized "Fix," a box of clothes for customers to try on.