Facebook parent company Meta posted lower fourth-quarter profit and revenue on Wednesday, hurt by a downturn in the online advertising market and competition from rivals such as TikTok. But the company’s stock soared in extended trading, as its revenue beat Wall Street’s muted expectations and the Menlo Park, California-based company announced a $40 billion stock buyback. Meta Platforms Inc. said it earned $4.65 billion, or $1.76 per share, in the final three months of 2022. That’s down 55% from $10.29 billion, or $3.67 per share, a year earlier. Analysts were expecting earnings of $2.26 per share, according to a poll by FactSet. Revenue fell 4% to $32.17 billion from $33.67 billion. Analysts were expecting $31.55 billion. Meta’s shares jumped almost 18% in after-hours trading.