Foreign Investors Sold Rp355 Billion the Same Day the IHSG Rose 0.75%
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5 min read
On 18 August 2026, the IHSG closed 0.75% higher, up 47.94 points to 6,449.83. In that same trading session, foreign investors net sold Rp355.2 billion of Indonesian stocks. If "foreign money is leaving" always meant "the index falls," those two numbers should not have moved in opposite directions on the same day. Here is what foreign net sell data on the IDX actually measures, and why a headline about it does not automatically tell you where a stock or the index is headed next.
Every trading day, the IDX and the data providers that track it report two rupiah figures for foreign-registered brokerage accounts: how much they bought, and how much they sold. If the amount sold is bigger than the amount bought, that day is a "net sell" day. If buying wins, it is a "net buy" day.
This is a flow number for one day, or a period you add several days together. It is not the same thing as how much of the IDX foreigners still own overall, that is a separate figure usually called foreign ownership or kepemilikan asing, and it moves far more slowly. Net sell data comes straight from actual executed trades, so the rupiah figure itself is precise. What it does not come with is an explanation of why the trades happened.
Tuesday 18 August 2026 is a clean example. Foreign investors bought Rp4.32 trillion of Indonesian stocks and sold Rp4.67 trillion, a net sell of Rp355.2 billion. The IHSG still closed up 0.75% that day, at 6,449.83, on total exchange turnover of Rp14.83 trillion (Kompas Money, 18 August 2026).
Three stocks led the foreign selling that day (CNBC Indonesia, 19 August 2026):
| Stock | Foreign net sell |
|---|---|
| Indosat (ISAT) | Rp191 billion |
| Bank Rakyat Indonesia (BBRI) | Rp170 billion |
| Astra International (ASII) | Rp48 billion |
None of that selling stopped the IHSG from rising. Domestic buying, in these three names and elsewhere, absorbed it.
Foreign investors used to make up close to half of the IDX's daily trading value, roughly 46% in the second and third quarters of 2024. Their share fell to about a third by the end of that year and has only recovered to about 39% as of the second quarter of 2026 (Katadata, "Elegi Bursa Saham Indonesia, Mengapa Investor Asing Terus Menjauh?"). A separate tally from early August 2026 puts foreign investors at just 38% of the exchange's year-to-date trading composition, with domestic investors, individuals, mutual funds, insurers and pension funds combined, making up the other 62% (Bisnis.com, 7 August 2026).
When foreign investors were closer to half of daily turnover, their net flow moved the index almost mechanically: heavy selling had nowhere to be absorbed. With domestic investors now routing more than three in every five rupiah traded, a foreign net-sell day can be offset by domestic buying without the index falling at all. That is exactly what happened on 18 August.
Foreign flow is not always just noise. Five days earlier, on 13 August 2026, MSCI announced the results of its August index review: PT GoTo Gojek Tokopedia Tbk (GOTO) was removed from the MSCI Global Standard Indexes, and PT Charoen Pokphand Indonesia Tbk (CPIN) was downgraded to the Small Cap index, both changes effective after the close of trading on 31 August 2026. The IHSG fell 1.13% that day, to 6,301.77 (Bisnis.com, 13 August 2026).
That looks like a fundamentals story until you check the actual scale of the change: Indonesia's own weight in the MSCI Emerging Markets Index only moved from about 0.49% to about 0.46% as a result (CNBC Indonesia, 13 August 2026). The selling that day came largely from index funds mechanically rebalancing their holdings to match MSCI's rulebook, not from a reassessment of what GOTO or CPIN are actually worth. NetWort has covered the same week from a different angle, tracing how much of that move actually came from a US inflation report released the day before rather than from MSCI. Both pieces land on the same lesson from different data: the trigger behind a foreign-flow headline matters more than the headline number itself.
Zoom out from single days and the total adds up. Foreign investors had net sold Rp72.52 trillion in the regular market on a year-to-date basis as of 6 August 2026 (Bisnis.com, 7 August 2026). That figure is a snapshot, not a fixed total: it grows on every additional net sell day and shrinks on every net buy day, so treat any specific rupiah figure you see quoted, including this one, as dated to whatever day it was reported.
A single day's, or even a single week's, foreign net sell figure does not tell you where a specific stock or the IHSG is headed next. Before reacting to one, check what domestic flow did the same day, and check whether the selling is concentrated in a handful of large index-weighted names or spread thin across the market. NetWort's Market page shows today's sentiment and top movers together, so you can see whether a net sell headline lines up with an actual index move or not. If a stock like Bank Rakyat Indonesia (BBRI) shows up on a net-sell list you are watching, its own price and volatility history is a better guide than the flow figure alone.