80 Stocks on HSC List to Be Excluded from IDX Composite Calculation

The Indonesia Stock Exchange (IDX) has decided to exclude all shares with a high level of ownership concentration, or High Shareholding Concentration (HSC), from the calculation of the IDX Composite (IHSG). The policy covers 80 shares identified as belonging to the category.

IDX President Director Jeffrey Hendrik said HSC shares would no longer be included in the IHSG calculation. They had previously been excluded from several of the IDX’s flagship indices: IDX30, LQ45 and IDX80.

“We will exclude all High Shareholding Concentration shares from the IDX Composite,” Jeffrey told reporters at the IDX building in Jakarta on Monday, 19 October 2026.

He said the policy continued the IDX’s earlier move to prevent HSC shares from being included in several of Indonesia’s main capital-market indices.

“HSC shares have already been excluded from, or are ineligible for, several flagship indices, such as IDX30, LQ45 and IDX80. Going forward, all High Shareholding Concentration shares will also be excluded from the IHSG calculation,” Jeffrey added.

Although they will be removed from the index calculation, the shares will remain available for normal trading on the IDX. The change concerns only their role in forming the index, meaning their price movements will no longer affect the IHSG.

HSC shares account for 18 per cent of the IHSG

Jeffrey said the policy was intended to provide a more realistic picture of the IHSG’s movements. Shares with concentrated ownership were considered to pose risks that should be taken into account when measuring overall market conditions.

Removing these shares is expected to make the IHSG a more representative reflection of stock-market dynamics.

“Therefore, to provide a more realistic picture through the IHSG, we will exclude all HSC shares from it,” he said.

Jeffrey said HSC shares currently account for about 18 per cent of the IHSG’s weighting. The policy will therefore change the composition of shares used to calculate Indonesia’s main stock-market index.