Trading on Margin at an IDX Broker Comes With a Forced-Sell Trigger You Don't Control
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7 min read
You put up Rp200,000,000 of your own money. Your broker lends you another Rp200,000,000 on top of it, so you control Rp400,000,000 of stock instead of just your own Rp200,000,000. That is margin trading. It also means that if the stock falls far enough, your broker can sell your position on a schedule fixed by regulation, on a specific trading day, without calling you first to ask.
Margin trading means borrowing money from your securities company to buy more stock than your own cash would cover, using the stock itself (and your own cash) as collateral for that loan. It is not available on a regular brokerage account. In Indonesia it runs under Otoritas Jasa Keuangan's (OJK, the financial services regulator) rules for securities financing, most recently POJK No. 6/2024, effective 3 October 2024, which sets out who can borrow, which securities firms can lend, and how the whole arrangement has to be managed.
To even open a margin account, OJK's rules require a customer to already have a net worth above Rp1,000,000,000 and annual income above Rp200,000,000, on top of holding a regular securities account. The initial collateral required is at least 50% of the position's value, or a fixed rupiah minimum set by OJK, whichever is higher. This is deliberately not a beginner product: a small account with modest savings does not qualify, regardless of how confident the investor feels about a particular stock.
Only a specific list of securities can be traded on margin at all. IDX (Bursa Efek Indonesia) publishes and periodically updates a "Daftar Saham Marjin dan Short Selling" (list of margin and short-selling eligible securities). To make that list, a stock that has traded for over a year generally needs to have been traded on at least 90% of trading days over the trailing six months, with average daily transaction value above Rp5,000,000,000, or above Rp250,000,000 combined with more than 500,000 shares traded a day, alongside liquidity, volatility and market-cap screens IDX runs internally. In its August 2026 update, IDX added 39 securities and removed 14, bringing the total eligible list to 352, per Indopremier's coverage of the announcement.
Passing that screen is only half of it. Which stocks on that list your own broker can actually finance for you depends on the broker's own Modal Kerja Bersih Disesuaikan (MKBD, adjusted net working capital, a regulatory capital measure every securities firm has to report). A securities firm with MKBD of at least Rp250,000,000,000 can typically offer margin financing across the full IDX-eligible list. A smaller firm is restricted to a narrower slice, often close to just the LQ45 index's 45 constituents. Two accounts at two different brokers, both technically "margin accounts," do not necessarily give you the same list of stocks to borrow against.
This is also why a stock carrying one of IDX's special notation letters, the warning codes BEI displays next to a ticker for things like a going-concern audit opinion or an unusual trading pattern, is the kind of stock that tends to drop off the margin-eligible list first: the volatility and reporting-quality screens above are built to catch exactly that risk profile. A stock's listing board is a related but separate signal; margin eligibility is its own, narrower filter on top of it.
Once you are actually holding a margin position, one number governs whether your broker can leave it alone or has to act: Margin Ratio.
MR = Financing amount ÷ Collateral value (after haircut)
"Haircut" here means the stock isn't counted at 100% of its market value as collateral. A more volatile or less liquid stock gets a bigger haircut, so the same rupiah position backs less borrowing than a stable blue chip would. Regulators set MR in three zones:
| Margin Ratio (MR) | What it means |
|---|---|
| 50% or below | Healthy. No action required. |
| Above 50%, up to 65% | Margin call zone. Broker asks you to add collateral or reduce the position. |
| Above 65% | Force-sell trigger. The clock described below starts. |
The 65% ceiling comes from IDX's Peraturan II-H, the exchange rule governing margin and short-selling transactions: a securities firm may finance at most 65% of a customer's collateral value, and once actual financing exceeds that share, the firm's own obligation to fix it kicks in, not just an option.
Here is the part that catches investors off guard. Once MR crosses above 65%, you get a margin call, a notice to add cash or securities to bring the ratio back down, for three consecutive trading days. If the ratio is still above 65% at the start of the fourth trading day, your broker is obligated under the same exchange rule to sell down the position itself, at that point, to bring MR back to 65% or below. This does not require your consent, your sign-off, or even a phone call reaching you. It is not the broker being aggressive; it is the broker meeting its own regulatory obligation to the exchange.
That also means the sale happens at whatever price the market offers that day. Nothing about the rule guarantees you a favorable exit, and if the sale proceeds still leave financing outstanding, that shortfall is still your debt to the broker, not something the forced sale automatically settles.
Say you put up Rp200,000,000 of your own money and your broker finances another Rp200,000,000, buying Rp400,000,000 worth of a margin-eligible stock. Ignoring haircuts for simplicity, here is what happens to MR as the stock's price falls:
| Price move from entry | Position value | Financing owed | Margin Ratio (MR) | Zone |
|---|---|---|---|---|
| 0% | Rp400,000,000 | Rp200,000,000 | 50.0% | Healthy |
| −10% | Rp360,000,000 | Rp200,000,000 | 55.6% | Margin call |
| −20% | Rp320,000,000 | Rp200,000,000 | 62.5% | Margin call |
| −26% | Rp296,000,000 | Rp200,000,000 | 67.6% | Force-sell trigger |
The financing amount does not shrink just because the stock has, since it is a fixed loan. Only the collateral side moves, which is exactly why a falling stock pushes MR up rather than down. Once that fourth row is reached and stays there for three trading days without a top-up, the countdown to the fourth-day forced sale is running.
None of this shows up if you never open a margin account, but it is worth understanding the mechanics before a broker pitches you one, since the pitch is usually about the upside, not the countdown on the downside. If you are weighing whether your own portfolio could absorb a price drop of the size in the table above without needing to sell anything, start with what you actually hold. Open NetWort's Holdings page and check your current invested amount against your own cash buffer. That is the same kind of collateral cushion a margin lender would be sizing financing against, except here it is entirely your own money and nobody else's countdown.