Bridgewater said in a statement that its new Singapore office marks its first Asian expansion beyond China in order to serve regional clients.
Citadel is opening an office in Tokyo and plans to market U.S. fixed income products in Japan, it said separately.
The U.S. firms' moves are another signal of how rising Sino-U.S. tension is encouraging western businesses to seek growth in Asia outside China, with investors behaving likewise.
Founded by long-time China bull and billionaire investor Ray Dalio, Bridgwater's Singapore location adds to offices in Beijing and Shanghai in the region and opens as the world's biggest hedge fund by assets cuts China equities exposure.
The Connecticut-based firm sold its entire stakes in Alibaba and JD.com in the second quarter of 2022, according to its latest 13F filing.
Chip Packard, head of Eurasia, said in the Bridgewater statement the new permanent presence would strengthen client relationships and open access to new opportunities.
Citadel, which has faced scrutiny in the U.S. over its practice of paying retail brokers for the right to execute their trades, said its Japan plans were part of a global expansion.
It intends to provide liquidity in Treasuries and dollar interest-rate swaps once it is granted membership in the Japan Securities Dealers Association.
"Japanese institutional investors have long played a critical role in the global fixed-income markets," Paul Hamill, the global head of fixed income distribution at Citadel, said in the statement.
(Reporting by Summer Zhen and Xie Yu in Hong Kong; Editing by Christian Schmollinger)
