Amazon Prime Day Is Already Making Retail Investors Miserable

Traditional retailers have spent at least a decade searching for a defense against the existential threat posed by the Amazon e-commerce empire. They’ve been largely unsuccessful so far—and on Monday, as Amazon Prime Day hype built to a deafening roar, retail investors seemed to acknowledge that, as several stocks in the sector took a beating.

The S&P Retail Select Industry Index shed just over 100 points, or 2.5%, on the day, and several individual retail stocks, including Macy’s (m) and Gap (gps), fared far worse. The retail sector was also hurt Monday by the announcement by teen clothing retailer Abercrombie & Fitch that it had given up trying to find a buyer. Abercrombie’s stock (anf) plunged more than 21% for the day, and many analysts see its woes as emblematic of the larger struggles of apparel retailers.

Prime Day, which technically begins Monday night and runs through Tuesday, has become a significant buzz-generator for the Seattle-based shopping giant, thanks in part to big, Black Friday-like discounts on electronics. While the company has been cagey about disclosing exactly how much business it does on the shopping day, Prime Day has become something of a customer-magnet for Amazon (amzn) in recent years, and a reminder to other retailers of their diminishing clout.

Investors are gloomier than usual about Amazon’s retail competition this month in the wake of the company’s announced acquisition of high-end grocer Whole Foods (take that, supermarkets!) and Nike’s confirmation that it would start selling shoes and other athletic gear via Amazon. (In your FACE, sporting-goods stores!)

In addition to Abercrombie, Monday’s big stock losers included:

Macy’s, which fell by just over 7%. The company has reported eight consecutive quarters of declining comparable sales. And the stock was hurt further by a report in the Wall Street Journal that it and other department store chains have begun offering discounts on high-end cosmetics—one of the few remaining bastions of high-profit-margin sales in the retail world.

Dick’s Sporting Goods (dks), also down more than 7% for the day. Dick’s would be among the biggest losers if Amazon were to make a bigger incursion into athletic-gear sales.

Gap Inc., owner of the Gap, Athleta, Banana Republic, and Old Navy brands, whose stock fell 6.3%.

Shares in Amazon were up 1.8% Monday, closing at $ 996.47. The stock has risen 33% year to date.