Shares of retailers Macy's (NYSE: M), Ulta Beauty (NASDAQ: ULTA), and Overstock.com (NASDAQ: OSTK) fell hard this week, down 18.4%, 15.5%, and 16.5% on the week, respectively, as of 1:38 p.m. ET today. None of these three stocks reported significant company-specific news this week, but bad earnings reports and outlooks from big-box retail bellwethers Walmart and Target decimated any and all retail names, these three included. This week, Walmart and Target both reported so-so revenue growth, but plummeting operating margins spooked investors.