Indonesia’s position, which it had held for nearly a decade, has now shifted. In mid-May 2026, Singapore’s stock market capitalization surpassed Indonesia’s, making the city-state the largest stock exchange in Southeast Asia.
Singapore’s market capitalization rose to approximately US$645 billion, overtaking Indonesia’s US$618 billion, according to Bloomberg data. This is no small achievement for a country of 5.9 million people surpassing an archipelagic nation of 280 million.
This shift did not happen overnight. Two opposing forces moved simultaneously: Singapore advanced through carefully designed market reforms, while Indonesia declined under layered pressures that had accumulated since the beginning of the year.
What Happened to Indonesia’s Market
Indonesia’s stock market experienced a major sell-off that erased more than 30% of its market value since January, according to Bloomberg data. Several triggers emerged almost simultaneously. Two global credit rating agencies issued coordinated warning signals for Indonesia.
Moody’s downgraded Indonesia’s sovereign credit outlook to negative, although the country’s credit rating itself remains at investment grade. Shortly afterward, Fitch Ratings followed suit, revising Indonesia’s outlook from stable to negative, citing rising policy uncertainty.
For foreign investors, two back-to-back signals from major rating agencies were enough to trigger exit decisions.
There were also concerns that global indices might downgrade Indonesia’s stock market status from emerging market to frontier market, a classification that typically forces large institutional investors to reduce or fully exit their holdings.
This pressure also pushed the rupiah to a critical level, briefly reaching Rp17,100 per US dollar, while foreign exchange reserves fell to their lowest level in nearly two years.
As a result, the Jakarta Composite Index (JCI) closed the week of May 18–22, 2026 at 6,162, down 8.35% in just one week. Total stock market trading value on the Indonesia Stock Exchange (IDX) also dropped 10.07%, from Rp11,825 trillion to Rp10,635 trillion, meaning more than Rp1,000 trillion was wiped out within seven days, according to official IDX data.
What Is Fueling Singapore’s Market Rally
While Jakarta was under pressure, Singapore was setting new records. The Straits Times Index (STI) crossed the 5,000 mark for the first time in 2026, and over the 12 months through April 2026, the index had already risen 29%, according to SGX data.
One of the key drivers was the Singapore government’s decision to inject dedicated funds to revive its stock market. Through the Monetary Authority of Singapore (MAS), the program was expanded to S$6.5 billion in 2026 (up from S$5 billion previously), with around S$3.95 billion already allocated to nine major asset managers, including BlackRock, Manulife, and Lion Global.
The impact is visible in the numbers. The total market capitalization of STI-listed companies rose from S$870 billion at the end of 2024 to S$1.1 trillion by the end of 2025. This increase of more than S$200 billion far exceeded the size of the government’s stimulus itself.
This suggests that Singapore’s market is not only being supported by policy measures but is also being actively trusted by investors.
Singaporean equities have attracted safe-haven inflows amid global volatility, as investors increasingly prioritize the country’s stability during periods of uncertainty.
What It Means for the Region
This shift in position is not merely statistical. Singapore’s strengthening role further reinforces its status as the primary listing and fundraising hub for REITs and regional financial sectors, potentially diverting IPOs and secondary listings away from Kuala Lumpur, Bangkok, and Jakarta.
Bloomberg views this shift as a signal of investor approval of Singapore’s market reforms, alongside a weakening confidence in Indonesia’s economic management. For neighboring markets, this may add pressure to accelerate their own reforms in order to avoid falling further behind in the competition for foreign capital.
