Reddit went public in march at $34 a share and has since seen its stock jump more than sixfold to $216.47 as of Wednesday's close. The shares were up 32% this year prior to the after-hours selloff.
Reddit's fourth-quarter earnings followed several other online advertising tech companies that recently reported their latest quarterly earnings.
Last week, Amazon reported fourth-quarter earnings, saying its online advertising business recorded $17.29 billion, up 18% from a year ago. In its fourth-quarter earnings, Pinterest said its sales in the period rose 18% year over year to $1.15 billion.