** Shares of Amazon.com AMZN.O down 2.5% on Thursday, among biggest laggards in Dow Jones Industrial Average .DJI and S&P 500 consumer discretionary index .SPLRCD

** Rival retailer Walmart WMT.N warned it will have to start raising prices this month due to high cost of tariffs

** The big-box and ecommerce retailer also said it is working with suppliers to substitute tariff-affected components

** WMT shares off 0.9%; but AMZN stock underperformed and it was eyeing second straight day of declines which had followed 5 days of gains including a 8% rally on May 12 after announcement of 90-day pause of U.S. 145% tariffs on Chinese goods

** Kim Forrest, chief investment officer at Bokeh Capital Partners said Amazon's sell off may be "a hangover from WMT’s guidance about changing supply chains. "Amazon is heavily dependent upon China, Forrest said

** AMZN shares last traded at $204.89; last down 6.5% YTD vs ~0.9% drop for DJI and 5.85 drop for consumer discretionary index .SPLRCD

(Reporting By Sinéad Carew)

((sinead.carew@thomsonreuters.com; +13322191897;))