IDX Corporate Insiders Can't Legally Trade on Secret Information. Here's What the Rule Actually Restricts
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6 min read
In mid September 2026, six top executives of PT Sarana Menara Nusantara Tbk (TOWR), a Djarum-linked tower company on the Indonesia Stock Exchange, sold a combined Rp98.04 billion of their own company's shares in a single week. Headlines like that make retail investors nervous. If the people who run the company are selling, shouldn't you sell too? Before reacting to a headline, it helps to know what Indonesia's IDX insider trading rules actually require, and what they do not.
Indonesia's insider trading rules, set out in Articles 95 through 98 of the Capital Market Law (Undang-Undang Nomor 8 Tahun 1995), do not ban a company's own directors, commissioners or major shareholders from ever buying or selling its shares. What the law actually bans is trading, or telling someone else to trade, while holding "informasi orang dalam": material information about the company that has not yet been made public and that could move the share price or change an investor's decision once it comes out. Think of a merger that is signed but not yet announced, or a quarterly loss the board already knows about but the market does not.
Break that rule and the penalty is a real criminal one, not just a fine paid quietly. Article 104 of the same law sets a maximum sentence of 10 years in prison and a fine of up to Rp15 billion for anyone convicted of trading on inside information under Articles 95 through 98. This sits in the same article as market manipulation and securities fraud, which tells you how seriously the law treats it on paper.
A useful way to see this is a separate OJK regulation, POJK Nomor 78/POJK.04/2017, which spells out securities transactions insiders are explicitly allowed to make even while holding inside information. Two situations qualify: a trade between two insiders who both already hold the same inside information, done off the exchange, and a trade between an insider and an outside party where the insider fully discloses the inside information first, and the outside party agrees in writing to keep it confidential and not use it for anything else.
Both carve-outs point at the same underlying idea. The problem the law is solving is an unfair information gap between two sides of a trade, not the mere fact that someone who happens to work at the company wants to buy or sell its stock. Close that information gap honestly, on the record, and the trade is legal.
If you have read about US or Malaysian listed companies, you may expect a fixed calendar window, often called a blackout period or closed period, during which insiders simply cannot trade at all, typically in the weeks before an earnings release. Bursa Malaysia's own Main Market Listing Requirements set out exactly this kind of structured closed period for directors and principal officers of listed companies.
Indonesia's Capital Market Law and its implementing OJK regulations do not set out an equivalent fixed closed period tied to the reporting calendar. Instead, Indonesia's system relies on the information-based prohibition in Articles 95 through 98 above, combined with the disclosure regime below. In practice this means an IDX insider can legally trade in the days before an earnings release, provided the trade is not based on material information about that release that the public does not yet have. Do not assume Indonesia mirrors a rule you may have read about for a different exchange.
Trading legally does not mean trading privately. Under POJK Nomor 4 Tahun 2024, which took effect in August 2024, any member of a public company's board of directors or board of commissioners who holds voting shares, and anyone who holds at least 5% of a public company's voting shares, must report their holdings and any change in them. The regulation shortened the reporting window from the previous 10 days down to as soon as possible and no later than 5 business days from the transaction.
These filings go through the exchange's own electronic reporting system and become public disclosures, which is exactly how financial media are able to report a story like six executives selling Rp98.04 billion in shares within days of it happening. The reporting rule does not stop an insider from trading. It makes sure the trade cannot stay a secret, so the rest of the market can weigh the same fact everyone else can see.
The TOWR case from the opening is worth walking through, because it shows why a disclosed insider sale is not automatically a signal to copy. According to reporting from IDX Channel, Kontan and EmitenNews, four directors, including president director Ferdinandus Aming Santoso, and two commissioners sold a combined 224.23 million TOWR shares at Rp437 per share on 16 September 2026, worth Rp98.04 billion. Santoso's own sale of roughly 97 million shares, worth about Rp42.39 billion, was the largest single piece of it.
EmitenNews reported that the shares involved had come from MESOP, the company's own management and employee stock option program, meaning these executives were largely cashing out options they had already earned, rather than dumping a fresh personal stake in the company on a whim. TOWR's share price kept falling anyway, closing at Rp414 by 18 September 2026, a 6.33% drop that day and an 8.81% decline over the prior five trading days. A retail investor who saw only the headline, "TOWR executives sell Rp98 billion in shares," and treated it as a warning sign would have been reacting to a legally required disclosure, not to genuine inside knowledge about why the stock was actually falling.
If a headline about insider selling makes you want to act, look at what the stock is actually doing rather than reacting to the report alone. NetWort's Market page shows a live IDX heatmap alongside gainers, losers and a market news feed, so you can see whether a stock is genuinely under pressure and read the coverage behind it, instead of trading off a single disclosure filing in isolation. This is a different mechanism from Unusual Market Activity notices, which flag suspicious price or volume patterns directly; if you want to understand that separate safeguard, see our explainer on what triggers a UMA notice on the IDX.