IDX Expands HSC Committee, Brings In Capital Group and UBS

The Indonesia Stock Exchange (IDX) officially expanded the membership of its High Shareholding Concentration (HSC) Committee to nine people on Monday, October 26, 2026. The committee used to consist solely of representatives from self-regulatory organizations (SROs), but now five of the nine seats go to independent external members.

IDX President Director Jeffrey Hendrik announced the change at a press conference at the exchange's Main Hall in Jakarta. "From the names who have already confirmed, our committee membership is now expanded to nine people. SRO directors only make up four, the other five are independent external parties," Jeffrey said, as quoted by ANTARA.

Who joined the new committee

Four seats from the SRO side are filled by two IDX directors, one director from PT Kliring Penjaminan Efek Indonesia (KPEI), and one director from PT Kustodian Sentral Efek Indonesia (KSEI), the clearing and custodian institutions.

The five independent seats are filled by figures from industry, academia, and foreign investment. From the brokerage industry, there's Alex Widi, President Director of Mandiri Sekuritas, and Joshua Arief Tanja, President Director of UBS Sekuritas. Prof. Dr. Mardiasmo, Chairman of the National Committee on Governance Policy, was brought in to ensure the committee's governance process runs properly. The academic seat goes to Prof. Dr. Eduardus Tandelilin.

The foreign investor seat was entrusted to F. Chapman Taylor of Capital Group, a portfolio manager with more than 30 years of experience in the global asset management industry.

Why the committee composition changed

Jeffrey explained the expansion is meant to strengthen governance around the methodology for determining which stocks enter or exit the HSC list. Until now, decisions on HSC status rested entirely with internal SRO representatives, without outside perspective.

"The HSC committee membership that used to consist only of SROs will be expanded to include independent parties from industry, academia, and investor representatives," Jeffrey said. He added that the committee retains flexibility to add members or invite independent resource persons to future meetings, enriching the discussion with broader perspectives.

Bringing in a foreign investor like Chapman Taylor is notable because it adds a voice from the data user side rather than just the market regulator. Foreign institutional funds are typically sensitive to concentration issues since they affect the liquidity of the shares they hold.

What HSC is and why it matters

HSC is a notation IDX assigns to stocks with ownership heavily concentrated in one party or a small group, usually controlling shareholders or their affiliates. High concentration leaves thin free float in the market, making such stocks prone to extreme volatility and vulnerable to abnormal price movements.

According to IDX data cited by ANTARA, 88 stocks have been listed or related to the HSC designation during the April to October 2026 period. Of that number, three issuers have had their HSC status revoked, while 85 others still carry the status as of now.

For investors, HSC status is not just an administrative label. Stocks carrying HSC status will be excluded from the IHSG (Jakarta Composite Index) calculation effective November 2, 2026, under a policy IDX previously announced. That means the weight of those stocks will no longer influence the benchmark index's movement, even though the shares remain tradeable as usual.

Market reaction so far

IDX's earlier move to exclude HSC stocks from the IHSG calculation had already drawn support from market analysts. Mirae Asset, for instance, said the decision to remove HSC stocks from the index was indeed necessary, according to earlier ANTARA reporting. Expanding the HSC Committee can be read as a continuation of efforts to refine the methodology behind that policy, aiming for a more transparent process that doesn't rely solely on the exchange's internal assessment.

What it means for investors

Investors holding stocks with highly concentrated ownership should track HSC status updates from IDX regularly, since the list can change with each review period. Stocks newly added to HSC lose their weight in the IHSG starting November 2, 2026, meaning their price movements will no longer directly affect the benchmark index even as they continue trading in the regular market.

For institutional investors, especially foreign ones, expanding the committee to include a name like Chapman Taylor from Capital Group could signal that IDX wants its HSC methodology to align more closely with governance standards used by global fund managers. This is worth watching since it could shape which issuers get flagged or cleared in upcoming reviews.

Retail investors trading stocks with small free float should check an issuer's HSC status on the official IDX website, as a status change can affect both liquidity and the market's risk perception of that stock.

Frequently asked questions

What is the HSC Committee at the Indonesia Stock Exchange?

The HSC Committee decides the methodology for designating High Shareholding Concentration stocks, shares with ownership heavily concentrated among one or few parties. It used to consist only of SRO representatives, and has now been expanded with five independent members.

Who are the new members of the HSC Committee?

New members include Alex Widi of Mandiri Sekuritas, Joshua Arief Tanja of UBS Sekuritas, Prof. Dr. Mardiasmo, Prof. Dr. Eduardus Tandelilin, and F. Chapman Taylor of Capital Group.

How many stocks currently carry HSC status?

Eighty-eight stocks have been listed or removed from the HSC list throughout 2026. Three issuers have had their status revoked, while 85 others remain under HSC status for the April-October 2026 period.

When will HSC stocks be excluded from the IHSG calculation?

Stocks with HSC status will be excluded from the IHSG calculation effective November 2, 2026, under IDX policy.