Meta Platforms (META) reported strong third-quarter results thanks to a rebound in advertising sales and continued cost discipline in CEO Mark Zuckerberg's "year of efficiency. However, warnings of a volatile start to ad spending in the fourth quarter that coincided with the war in the Middle East caused shares to give up their initial after-hours gains and trade lower. Revenue for the three months ended Sept. 30 climbed 23% year-over-year to $34.15 billion, beating analysts' forecasts of $33.56 billion, according to LSEG, formerly known as Refinitiv. Earnings per share grew 168% year-over-year to $4.39, exceeding Wall Street's estimates of $3.63....