Prime Day shopping events to entice cautious consumers and play defense against stiffer competition from the likes of Walmart Inc., Target Corp. and TikTok, who have launched their own discount days in response.

Online spending is expected to surge to $23.8 billion across U.S. retailers during a 96-hour Amazon Prime Day event this week, according to an Adobe Analytics forecast released on Monday, as shoppers seek strong discounts on back-to-school gear ranging from apparel to electronics.