Citic’s Black Monday Shows Its Challenge to UBS May Be Over

China’s stock-market collapse has put an abrupt end to Citic Securities Co.’s ascent among the world’s biggest brokerages by market capitalization.

Less than eight months ago, Citic came close to matching Switzerland’s UBS Group AG. Now, after a halving of Citic’s value to $27.5 billion, the Chinese firm is sinking closer to Japan’s Nomura Holdings Inc. Catching up with UBS at $81.3 billion once more looks like a distant prospect.