Indonesia Stock Exchange Purges "High Concentration" Stocks from Flagship Indices

JAKARTA, Investortrust.id — PT Bursa Efek Indonesia (BEI), the Indonesia Stock Exchange, is tightening the screws on its most prestigious indices. In a sweeping move to protect market integrity, the exchange has introduced new criteria for the IDX30, LQ45, and IDX80 indices, effectively blacklisting companies with highly concentrated ownership from joining these elite ranks.

This is a defensive play by the exchange to curb extreme volatility and potential "cornering" of the market. High Shareholding Concentration (HSC) often leads to low liquidity and "artificial" price surges that don't reflect true market value. By banning HSC stocks from the LQ45 and IDX30—the primary benchmarks for foreign and institutional fund managers—the exchange is signaling a commitment to transparency and genuine price discovery. Major players like Barito Renewables Energy (BREN) and Dian Swastatika Sentosa (DSSA) are among those currently categorized under this restrictive HSC watch.

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The "Concentration" Crackdown

The most market-moving change is the formal addition of the HSC exclusion. Under the new rules, any stock flagged for having too much power in the hands of too few shareholders will be disqualified from index evaluation.

This move targets "whale" stocks that may have high valuations but offer very little "tradable" room for the public. By excluding names like BREN and DSSA, the IDX aims to ensure that its benchmark indices represent companies where price movements are driven by broad market sentiment rather than the actions of a few majority owners.

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Liquidity and Free Float Adjustments

The exchange is also recalibrating how it measures a stock’s "tradability." For the IDX80—the index representing the 80 most liquid stocks with large caps—the exchange is offering a slight reprieve in trading frequency. Previously, a stock had to be traded every single day for six months to qualify; the new rule allows for a maximum of one non-trading day in that period.

Furthermore, the free float requirement—the portion of shares held by public investors—has been updated. While the minimum remains at 10%, the exchange will now defer to its more stringent "Regulation I-A" issued in March 2026. This means if the general listing rule requires a higher public sharking, the index criteria will automatically rise to match it.

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Dynamic Market Alignment

Exchange officials noted that these updates, effective as of April 22, 2026, are designed to "reflect more relevant market dynamics." The shift follows a series of updates to Circular Letter SE-00004/BEI/03-2026, which overhauled the definition of free float and shareholder limits.

By synchronizing these definitions, the exchange is forcing a higher standard of corporate governance. For investors, this likely means a more stable, albeit potentially slower-moving, LQ45 and IDX30, as speculative stocks with "thin" floats are pushed to the sidelines.