The following video is from Tuesday's Investor Beat, in which host Chris Hill and analysts Jason Moser and Andy Cross dissect the hardest-hitting investing stories of the day.

In today's edition, the guys discuss another monster quarter for Costco (COST -1.02%) and also weigh in on an eye-opening Morningstar report on the success of Amazon.com's (AMZN -0.40%) Prime service. Those stories, plus today's four biggest market movers, and two stocks our analysts are going to be watching closely this week.