HSC Stocks to Leave the JCI: What Changes?

The Indonesia Stock Exchange will exclude stocks classified as having High Shareholding Concentration (HSC) from the Jakarta Composite Index, or JCI, effective November 2, 2026. The change concerns index eligibility rather than the removal of those companies from the exchange. The policy and implementation date were confirmed in ANTARA’s report citing the exchange announcement.

Investors need to distinguish between two effects. The JCI’s composition will change, potentially altering the influence of its remaining constituents. The excluded shares, meanwhile, will continue to respond to trading activity, company performance, and shareholder decisions. Losing index membership does not automatically destroy a stock’s value, although portfolio adjustments can affect trading.

The useful question is therefore not simply whether the JCI will rise or fall after the change. Investors should examine how the index’s coverage will shift, which portfolios may need rebalancing, and which risks remain attached to HSC stocks after their prices stop contributing to the benchmark.

HSC stocks will be excluded from the JCI from November 2, 2026. Source: ANTARA, October 22, 2026, citing the Indonesia Stock Exchange. This is a news report, not a copy of the exchange announcement.

What Is Changing in the JCI?

The exchange is changing constituent eligibility rather than replacing the index’s entire calculation framework. HSC stocks will join Acceleration Board stocks among the shares excluded from the benchmark.

The methodology remains capped free float-adjusted market-capitalization weighting. In practical terms, weights reflect market capitalization adjusted for shares available to public investors, subject to a maximum constituent weight. That cap remains 9%, according to IDXChannel’s breakdown of the changes.

The review calendar will also change:

• Regular evaluations will take place in January, April, July, and October.

• The results will take effect on the first trading day of February, May, August, and November.

• Changes in HSC status outside regular reviews can trigger an incidental adjustment.

Weight caps and HSC exclusions address different issues. A cap limits the influence of an individual constituent. An eligibility rule determines whether that stock can enter the calculation at all.

Why Ownership Concentration Matters

Concentrated ownership can restrict the number of shares genuinely available to change hands. A large market capitalization does not necessarily imply deep trading liquidity. When the available supply is limited, a given transaction can cause a larger price movement than it would in a more liquid stock.

Free float is relevant, but it cannot explain every ownership connection, affiliation, or trading pattern. Investors should not attempt to reproduce the exchange’s HSC classification from a single ownership percentage. The designation used for index adjustments must follow the exchange’s determination.

Exclusion is also not proof that every HSC company has committed misconduct. Ownership classification, index eligibility, and a finding of wrongdoing are separate matters. Each requires its own evidence and decision-making process.

An 18% Weight Does Not Mean an 18% Index Move

On October 19, exchange President Director Jeffrey Hendrik said that 80 HSC stocks then accounted for roughly 18% of the JCI’s weight. He also clarified that index exclusion did not mean delisting. Those figures describe the position reported on that date, not the final November implementation list. Source: ANTARA, October 19, 2026.

An index weight cannot be translated directly into a gain or loss when constituents are removed. Index calculations use a divisor to preserve continuity through composition changes unrelated to price movements. This general function is explained in S&P Dow Jones Indices’ index mathematics methodology.

Consider a simplified hypothetical example:

• An eligible capitalization value of 1,000 units divided by a divisor of 0.2 produces an index level of 5,000.

• Removing some constituents reduces the eligible value to 800 units.

• Adjusting the divisor to 0.16 keeps the index at 5,000.

The example illustrates continuity, not an official simulation of the JCI adjustment. Actual divisors, constituent weights, and implementation procedures remain subject to the exchange’s rules.

Price changes caused by investor transactions are a separate issue. Rebalancing sales could pressure particular shares, while purchases could support others. Estimating that effect requires evidence about fund holdings and trading liquidity, not just the weight being removed.

Different Investors Face Different Consequences

A. Investors Holding HSC Shares Directly

Index exclusion does not erase share ownership. The investment’s economic value remains connected to the company’s assets, earnings, cash flow, liabilities, and governance. The benchmark change does not automatically improve or weaken those fundamentals.

Execution risk still matters. An investor selling a large position may encounter a wide bid-ask spread or limited order-book depth. A temporary increase in volume around the adjustment is also insufficient to establish that sustained demand has developed.

B. Products That Replicate the JCI

Products mandated to replicate the index face the most direct portfolio implications. When the benchmark changes, managers must manage the difference between their holdings and the index, known as tracking error, according to the product’s replication method and rules.

It would nevertheless be misleading to assume that every affected fund must sell all its HSC holdings at the same moment. The required transactions depend on assets under management, actual positions, execution strategy, and whether the fund uses full replication or another approach.

C. Active Funds Using the JCI as a Benchmark

Using the JCI to compare performance does not necessarily require a portfolio to hold every constituent. An active manager may have different discretion, depending on the prospectus and investment restrictions.

Investors should examine the mandate rather than treating all Indonesian equity funds as index trackers. Benchmark changes can alter relative performance comparisons, but decisions to retain or sell individual stocks must be assessed against each product’s rules.

D. Investors Using the JCI to Read the Market

A different constituent set changes the information captured by the benchmark. Once a stock is excluded, its price no longer helps explain movements in that index, even though it still affects its shareholders’ wealth.

Investors should supplement the JCI with market breadth, trading value, and sector performance. A rising headline index does not automatically mean that most stocks are advancing or that most portfolios are recovering.

Index Changes Do Not Replace Company Analysis

A technical benchmark adjustment should be separated from a change in business quality. A stock receiving a higher relative weight does not automatically become cheaper. A stock removed from an index does not necessarily become attractive after selling pressure.

A useful review can focus on:

• Ownership disclosures and subsequent changes.

• Earnings quality and cash generation.

• Related-party transactions and governance.

• Spreads, trading value, and execution depth.

• The mandate and actual holdings of any investment product used.

Changes to the JCI also do not automatically determine decisions by global index providers. Their eligibility standards, review processes, and final decisions must be examined separately.

What to Watch Before November 2

Further implementation disclosures should clarify which stocks are removed and how remaining constituent weights are adjusted. Fund-manager communications also matter, because potential trading pressure depends on actual portfolios rather than the HSC list alone.

After implementation, success should not be judged simply by whether the JCI rises. The more useful test is whether the benchmark better represents investable trading conditions while transparency and liquidity improve.

The exclusion changes the market’s measuring tool. Investors still need to assess the shares themselves through company fundamentals, ownership structures, and the ability to transact at a reasonable price.

Disclaimer: This article provides general information and analysis, not a recommendation to buy or sell shares or investment products. Index rules, HSC classifications, and constituent lists may change. Consult the latest exchange announcements and product documents before making an investment decision.