Little-known firm's $175-bn dip erases more value than Goldman's m-cap

Even after a retail frenzy that saw GameStop become the hottest stock in the world and a dog-themed joke cryptocurrency gain billions in value, the whirlwind trading in an obscure Hong Kong financial business stands out as spectacular.

The rapid rise of AMTD Digital — a barely profitable financial services firm — is a tale that, while reminiscent of last year’s meme-stock frenzy, is even more mysterious. In a move that has puzzled the financial community, the company’s shares skyrocketed in less than three weeks from their $7.80 initial public offering price to an intraday high of $2,555, an eye-popping jump