A Rp5,000 Stock and a Rp150 Stock Don't Move in the Same Size Steps. Here's What Fraksi Harga Actually Sets
5 min read
Loading...
5 min read
Look at any IDX order book and you'll never see a bid or ask that ends in an odd number like Rp6,713. Prices only exist at fixed steps, and the size of that step depends on how expensive the stock already is. That rule is called fraksi harga, and it quietly decides how finely a stock's price can actually move, whether you're placing a limit order on a Rp6,000 blue chip or a Rp40 penny stock.
Fraksi harga, literally "price fraction" and usually translated as tick size, is the smallest amount a stock's price is allowed to move on the IDX (Bursa Efek Indonesia). You cannot place an order at just any rupiah figure. Every price has to land on one of the exchange's fixed steps for that stock's current price band, and the step gets bigger as the stock's price does.
This isn't a technical footnote. It sets the tightest possible gap between a buyer's bid and a seller's ask (the bid-ask spread), and it decides exactly how many price levels exist between where a stock trades now and where it might trade next.
IDX sets fraksi harga under its own trading rule, Peraturan Nomor II-A (tick-size bands set in Kep-00023/BEI/04-2016, still in force under the March 2023 update, Kep-00055/BEI/03-2023). Five bands cover every listed stock:
| Price band | Minimum tick (fraksi harga) |
|---|---|
| Below Rp200 | Rp1 |
| Rp200 to Rp500 | Rp2 |
| Rp500 to Rp2,000 | Rp5 |
| Rp2,000 to Rp5,000 | Rp10 |
| Rp5,000 and above | Rp25 |
Bank Central Asia (BBCA), the IDX's largest company by market value, traded around Rp6,700 on 6 September 2026 (TradingEconomics), squarely in the top band. Its price can only move in Rp25 steps: Rp6,700, Rp6,725, Rp6,750, and so on. There is no valid order at Rp6,710.
At the other end, Receh.in's own 4 September 2026 roundup found 67 IDX-listed stocks trading below Rp50 a share, all sitting in the under-Rp200 band where the tick is Rp1, the smallest step the exchange allows.
The point of scaling the tick to the price is to keep the minimum possible move roughly proportional across very differently priced stocks, rather than letting a cheap stock swing by huge percentages on a single tick or an expensive one crawl in economically meaningless increments.
Rp25 on a Rp6,700 stock like BBCA is about 0.37% of its price. Rp1 on a Rp40 stock is about 2.5% of its price, a much bigger percentage jump for a single tick. The table doesn't make every band's percentage step identical, but it stops the gap from IDX's cheapest to its most expensive listings from becoming absurd: without wider ticks at the top, a Rp6,700 stock would move in the same Rp1 increments as a Rp40 one, an amount too small to matter at that price, and order books would fill with meaningless price levels.
The tick a stock uses isn't fixed to the company. It's fixed to whatever price band the stock currently sits in, so a stock that moves from one band to the next starts trading in a different step size immediately, with no announcement needed beyond the price move itself.
A stock split is the clearest example, because it moves a stock's price instantly rather than gradually. PT Dian Swastatika Sentosa Tbk (DSSA) closed at Rp67,000 on 8 April 2026, the last trading day before its 1-for-25 stock split (Investor.id, Indopremier). At Rp67,000, DSSA sat in the top band, trading in Rp25 steps. When the split took effect on 9 April 2026, the theoretical adjusted price fell to Rp2,680 (Harianbasis.co, Asatunews.co.id), which is exactly Rp67,000 divided by 25. That new price landed inside the Rp2,000-to-Rp5,000 band, where the tick is Rp10, not Rp25.
The same crossing happens in reverse when a stock rallies. A stock climbing from Rp4,800 to Rp5,100 doesn't just get more expensive, it moves out of the Rp10-tick band and into the Rp25-tick band, and every limit order placed above that threshold has to land on the wider grid from that point on.
If you trade near a band boundary, the tick size you think you're working with can change without warning the moment the price crosses it. A limit order priced at an increment that was valid a moment ago can become invalid once the stock moves into the next band, and the practical effect is most visible in exactly how tight a spread can get: the minimum possible bid-ask gap on any stock is one tick, so a stock sitting in a wider-tick band has a wider floor under its spread than the same stock would have one band down.
Before placing a limit order close to a round price level, check which band the stock currently sits in. NetWort's BBCA asset page shows a stock firmly inside the top, Rp25 band, the kind of price level where a decimal-looking order gets silently rejected because it doesn't land on a valid tick.