IDX Sectoral Classification (IDX-IC): How to Use Sector Indices for Peer Benchmarking

IDX-IC Explained: How Indonesia's Sector Classification System Works

In January 2021, Indonesia Stock Exchange retired the old JASICA sector system and replaced it with IDX Industrial Classification, known as IDX-IC. The new system groups every listed company into a primary sector based on globally recognized standards, making Indonesian stocks easier to compare against international peers using the same industry framework analysts already use abroad.

IDX-IC organizes companies through four levels: sector, sub-sector, industry, and sub-industry. A mining company sits under Energy or Basic Materials at the top, then narrows down through a sub-sector and industry tier to a specific sub-industry like coal or metal ore mining, giving investors far more precision than the old single-tier JASICA groupings ever offered on the same exchange.

The reclassification moved several familiar names into different sectors than investors expected when the system first launched. Telecommunication companies shifted into a dedicated Infrastructure sector alongside toll roads and utilities, while digital economy names landed in Technology or Consumer Cyclicals depending on their core revenue model, catching some longtime shareholders off guard when their holding's peer group changed overnight.

The Eleven Primary Sectors Under IDX-IC

IDX-IC organizes the exchange into eleven primary sectors, each tracked by its own sectoral index published alongside the composite IHSG. Knowing which sector a stock belongs to matters because sector-level indices move on different drivers than the broad market, and screening within a sector produces far more relevant peer comparisons than screening the whole exchange at once.

• Energy: coal, oil and gas, energy services
• Basic Materials: metals, chemicals, cement
• Industrials: construction, capital goods, transportation equipment
• Consumer Non-Cyclicals: food, beverage, retail staples
• Consumer Cyclicals: automotive, retail discretionary, media
• Healthcare: pharmaceuticals, hospitals, medical devices
• Financials: banks, multi-finance, insurance
• Properties and Real Estate: developers, REITs
• Technology: software, e-commerce platforms, digital banks
• Infrastructure: telecom, toll roads, utilities
• Transportation and Logistics: shipping, ports, logistics

Each sector index is float-adjusted and market-cap weighted the same way the broader IDX indices are, which means a handful of large-cap names can still dominate a sector index's daily movement even when most smaller constituents in that same sector are actually moving in a different direction on the same trading day.

A newer, smaller sector like Technology behaves very differently from a well-established one like Financials, since a thinner roster of constituents means one or two large listings can swing the entire sector index far more than a single bank swings the much broader Financials sector on its own.

This uneven weighting is worth checking before drawing a conclusion from any sector index move. A headline claiming the Technology sector rallied five percent means far less once an investor sees that a single large constituent, not a broad move across the sector's other listings, actually drove nearly the entire gain that day.

How Sector Indices Move Differently From the IHSG

The IHSG blends every listed stock into one number, which smooths out sector-specific swings that matter enormously to someone holding a concentrated position in a single industry. A banking-heavy rally can lift the composite index while energy and basic materials stocks quietly sell off underneath it, invisible unless you are watching IDX-IC sector indices directly rather than the headline figure alone.

Commodity-linked sectors, Energy and Basic Materials in particular, tend to track global commodity price cycles more closely than domestic economic data, while Financials and Consumer Non-Cyclicals move more in step with Bank Indonesia rate decisions and domestic consumption trends that have little to do with what coal or nickel prices are doing on any given week.

Watching the spread between sector indices over a rolling period tells you whether the current rally or selloff is broad-based across the exchange or concentrated in one or two sectors, which changes how much conviction a single-stock signal deserves in that environment before committing fresh capital to it.

Using IDX-IC for Peer Benchmarking

Comparing a stock's valuation multiple against the whole market tells you almost nothing useful, since a bank and a coal miner never trade on the same PER band for structural reasons that have nothing to do with either company's actual quality, growth outlook, or capital efficiency relative to its own specific line of business.

IDX-IC's sub-industry tier solves this by grouping a company with its truest peers rather than its broad sector. A coal miner should be compared against other coal sub-industry names, not against the entire Energy sector that also includes oil and gas services companies with a completely different cost structure and capital cycle.

When a stock's PER or EV/EBITDA sits meaningfully above or below its sub-industry median, that gap is the actual signal worth investigating, not the stock's position relative to the IHSG average, which mixes hundreds of unrelated business models into one number that says almost nothing about any single company's relative value.

Sector Rotation Signals Hidden Inside IDX-IC Data

Tracking relative performance across IDX-IC sectors over trailing one, three, and six month windows reveals rotation patterns before they show up as an obvious theme in daily news coverage. Money tends to flow into commodity sectors ahead of a global cycle upswing and into Financials ahead of an expected Bank Indonesia rate cut cycle, well before either move becomes a headline story.

• Compare each sector index's trailing return against the IHSG, not in isolation
• Watch for two or more sectors accelerating together, which signals genuine breadth
• Treat a single sector's outperformance with caution until foreign flow data confirms it

A sector accelerating on thin volume and narrow foreign participation often fades quickly once the initial momentum buyers take profit, while a rotation confirmed by sustained foreign net buying across multiple names in that sector tends to have far more durability behind it over the following weeks.

Where IDX-IC Falls Short

Reclassification changes a company's peer group without changing its actual business overnight, so a name freshly moved into Technology from Consumer Cyclicals may still carry legacy multiples and investor expectations from its old sector for a year or more after the formal reclassification date actually takes effect on the exchange.

Conglomerates with multiple unrelated business lines get filed under whichever segment generates the most revenue, which can misrepresent a company's true risk profile if a smaller but faster-growing segment is what actually drives the stock's future earnings trajectory rather than the legacy business the classification is built around.

IDX-IC also does not capture cross-border revenue exposure at all. Two companies in the same sub-industry can carry very different currency and export risk depending on how much revenue comes from overseas, a detail the classification system has no way to reflect since it groups purely by business activity, not by where that revenue is ultimately earned.

Building IDX-IC Into a Screening Workflow

A useful screening workflow starts by picking the sub-industry relevant to the thesis, pulling every constituent in that group, then ranking by valuation, growth, and balance sheet quality within that narrow peer set rather than against the exchange as a whole, which dilutes the comparison with unrelated businesses.

StockPilot's screening tools let an investor filter directly by IDX-IC sector and sub-industry alongside fundamental and technical criteria, so a search for undervalued names inside a specific sub-industry returns a peer-accurate shortlist instead of one diluted by unrelated businesses sharing only a broad sector label in common.

The same filter also works in reverse for risk management. An investor already holding several IDX positions can check whether those holdings are unintentionally concentrated in one or two sub-industries, a concentration that a portfolio view organized by ticker alone would never surface on its own.

The Takeaway on Sectoral Classification

IDX-IC gives Indonesian stock investors a peer-comparison framework that finally matches international standards, but the classification only adds value when it is used at the sub-industry level rather than the broad sector level most casual investors default to when screening the market.

Anyone screening or benchmarking IDX stocks should treat the sub-industry, not the sector name, as the real unit of comparison, and pair it with foreign flow data before reading too much conviction into a single sector's short-term outperformance relative to the broader index.

Over time, checking a holding's sub-industry median on every earnings season becomes as routine as checking the stock's own price chart, and it is often the faster way to spot a valuation gap opening up long before the broader market narrative catches up to it.

Start with the sectors you already hold positions in, build the sub-industry comparison habit there first, then expand it to new screening ideas once it becomes second nature rather than an extra step you have to remember to do.