The Jakarta Stock Exchange (IDX) is strengthening its defences against share price manipulation after the steepest two-session decline in Indonesian market history, triggered by a warning from MSCI about a possible downgrade. A broader oversight committee, proactive investigations and account freezes are due to take effect in November. The regulator is trying to answer criticism from an index provider that weighs on the market’s appeal to foreign investors.
🔑 Key takeaways
- The IDX is widening its committee that flags highly concentrated shareholdings to include independent experts, including academics and foreign investor representatives.
- Investigations and account freezes will be triggered as soon as coordinated trading is detected, with implementation planned for November 2026.
- The benchmark index suffered its heaviest decline on record over two sessions, on October 16 and 19, 2026, hitting its lowest level since 2020.
- MSCI is now weighing a possible downgrade to standalone market status, a harsher outcome than the January 2026 warning about frontier market status.
A broader committee with independent experts
On October 26, 2026, the exchange announced that it would widen the committee responsible for identifying stocks with highly concentrated shareholdings. Until now, the body was made up solely of market authority officials. It will now include independent experts, among them Indonesian academics and representatives of foreign investors. IDX chief executive Jeffrey Hendrik presented F. Chapman Taylor as one of the new members. A former partner at the investment firm Capital Group, Taylor currently advises the Indonesian sovereign wealth fund Danantara.
The financial regulator, the Financial Services Authority (OJK), backs the move. Hasan Fawzi, the regulator’s capital markets supervisor, has urged the IDX to strengthen its monitoring tools, in particular its ability to spot irregular trading patterns and detect coordinated trading.
“We encourage the IDX to strengthen the mechanism and methodology of transaction surveillance, including its capacity to identify irregular trading patterns, detect coordinated trading and reinforce its response mechanism to such events.”
Hasan Fawzi, Capital Markets Supervisor, Indonesian Financial Services Authority
The inclusion of outside voices is meant to lend credibility to the committee’s decisions. It is nonetheless controversial, since some of the appointees have ties to influential financial players at home and abroad.
Proactive investigations replace reactive alerts
Until now, surveillance relied mainly on a reactive procedure. When a stock moved sharply, the IDX warned the public of unusual market activity and asked the company concerned for an explanation. That process could also lead to a temporary trading suspension.
The new framework is presented as more proactive. It is designed to trigger as soon as coordinated trading is detected, with two main levers: opening investigations and freezing the accounts of investors deemed suspicious. The approach relies on analysing transaction patterns, a tool already used by market authorities in other jurisdictions.
The limits of the framework
A study published on June 27, 2026 in the Customary Law Journal notes that the effectiveness of surveillance remains constrained by evolving manipulation methods, particularly when schemes run through social media or nominee accounts. Freezing accounts does not solve the problem if schemes shift quickly from one account to another.
The backdrop: MSCI’s warning and a record rout
The announcement follows a warning from MSCI that Indonesia could be reclassified as a standalone market. The index provider cites a lack of transparency in transactions and insufficient measures to end coordinated trading. MSCI still classifies the country as an emerging market, but the threat is considerably more serious than the one issued in January 2026.
| Element | January 2026 | October 2026 |
|---|---|---|
| MSCI warning | Possible downgrade to frontier market status | Possible downgrade to standalone market status |
| Current status | Emerging market | Emerging market |
| Market reaction | Selloff followed by a price manipulation probe | Steepest two-session decline on record |
The October warning produced the largest stock market decline ever recorded in Indonesia, over the sessions of October 16 and 19, 2026. The benchmark index hit its lowest level since 2020 before rebounding. At 3:20 a.m. GMT on Monday it was still down about 0.6%, while the rupiah fell 0.4% to its weakest level since July.
The market had already been shaken in January. Bloomberg reported on January 31, 2026 that the collapse had prompted a probe into price manipulation and a statement from President Prabowo Subianto. In an analysis published on February 5, Nikkei Asia described the episode as exposing long-standing manipulation problems. The available sources do not specify the exact size of the January decline or the scope of the probe.
President Prabowo took a combative line at a cabinet meeting, saying MSCI was trying to “intimidate” Indonesia and that the country was not afraid. According to Reuters, Fawzi described local investors as “mature” and “wise”, noting that they had bought shares of companies with solid fundamentals after the announcement.
A string of reforms
A possible downgrade of Indonesia sits within a series of reforms launched since MSCI’s January warning. The country has published more detail on investor accounts and ownership data, raised the minimum free float requirement and announced record fines against players involved in manipulation. The government has also told MSCI and FTSE Russell that Indonesian regulators remain committed to market reform.
Buybacks illustrate the same logic. The rule allowing a company to repurchase its own shares without prior shareholder meeting approval has been extended to June 2027. Any such transaction must nonetheless respect the minimum free float, meaning the number of shares that must remain available to trade.
The legal framework and the « gorengan » mechanism
Indonesian law explicitly prohibits share price manipulation. According to the study by Gneissa Beltsazar, Lastuti Abubakar and Tri Handayani of Padjadjaran University, the practice is banned by Capital Markets Law No. 8 of 1995, in particular articles 90 to 93. The authors classify these practices as market abuse.
The authors use the term “gorengan stocks” for schemes known locally as “inflate then sell”. The pattern typically unfolds in four steps:
- Accumulate a large block of shares at a low price.
- Gradually push the price higher while promoting the stock to attract retail investors.
- Sell shares at elevated levels.
- Dump the remaining holdings, which drives the price down and leaves retail buyers trapped at inflated valuations.
The study assigns the OJK a central role in supervision and enforcement, and the IDX responsibility for order and transparency in trading. It warns that such practices can cause financial losses, erode investor confidence and damage the international perception of the quality of Indonesia’s capital markets.
Conclusion: outlook and scenarios
The IDX’s bet is that its surveillance can anticipate manipulation rather than punish it after the fact. If the broadened committee produces transparent decisions and account freezes are applied without selectivity, market credibility could recover and weigh favourably in MSCI’s next review. The signal would be stronger still if the free float and ownership disclosure reforms are applied consistently.
The adverse scenario remains real. A downgrade to standalone status would complicate access for passive investors who track MSCI indices, with potential consequences for capital flows and liquidity. A framework perceived as discretionary could also discourage foreign investors. In the coming months, the Indonesian market will need to show that its measures produce measurable effects on trading practices.
Sources
- Reuters, October 26, 2026
- Bloomberg, January 31, 2026
- TradingView (Reuters wire)
- CNA, post relayed on Threads
- Nikkei Asia, February 5, 2026
- Customary Law Journal, June 27, 2026
Cet article est publié à titre informatif et éducatif. Il ne constitue en aucun cas un conseil en investissement. Faites vos propres recherches (DYOR) avant toute décision.
