Mobvoi Inc., a Chinese artificial intelligence developer backed by Alphabet Inc.’s Google, dropped as much as 22% in its first day of trading in Hong Kong, marking the third stock debut to flop in the city this week.The shares tumbled even after they were sold near the low end of the indicated price range for its initial public offering. The company and its shareholders raised HK$321 million ($41 million), much lower than $200 million to $300 million it was said to be targeting last year. The sl...