The world's biggest online social network knocked the world's largest retailer out of the top 10 list of the highest-valued companies in the Standard & Poor's 500 index on Monday and the gap widened on Tuesday.
While the switch is mostly symbolic — nothing specific happened this week to warrant it, and the difference between the two giants is not that big — it signals investors' insatiable appetite for successful tech stocks. Apple, Microsoft and Google top the list of the highest-valued companies in the U.S., and Facebook looks to be on its way to joining them.
