Investors might be concerned that Roblox's growth momentum is slowing down. The 21% year-over-year growth in bookings was strong, but not when compared to the 25% growth rate Roblox reported in the fourth quarter of last year. Growth rates in the daily active user base, as well as in average bookings per user, both declined as well.

Roblox (RBLX) shares swooned Thursday after the company reported fewer-than-expected users in the fourth quarter. The online game platform had 85.3 million average daily active users in the period, up 19% year-over-year but below the analyst consensus of 88.