China's efforts to stimulate its economy are turning the nation's biggest brokerage into a bond-market powerhouse.

CITIC Securities Co overtook HSBC Holdings Plc in 2015 as top arranger for emerging-market debt securities worldwide as rate cuts by the People's Bank of China, the central bank, reduced borrowing costs and boosted yuan-denominated bond issuance in the onshore market, data compiled by Bloomberg show.

CITIC last year managed the equivalent of almost $53 billion worth of offerings with maturities of 18 months or more, almost all of that yuan-denominated, or 4.3 percent of the global market. HSBC, which dominated the developing-world bond market from 2008 to 2014, managed $46.2 billion worth for a second-place market share of 4 percent.