Poseidon Corporate Services Ltd entered UNSP
Not disclosed above 1% in Bakrie Sumatera Plantations Tbk last period. The stake now stands at 55.64%.
Monthly ownership analysis · KSEI
IDX Substantial Shareholder Changes
31 August 2026 versus 31 July 2026
August 2026 disclosures, comparing 31 July 2026 with 31 August 2026, recorded 131 new disclosed positions and 167 exits. UNSP was the standout, as Poseidon Corporate Services Ltd appeared with 55.64% while its concentration score rose from 24 to 55.
154clean position changes
118genuine new holders
154positions fully exited
12re-registrations (excluded)
Summary
- The month recorded 76 accumulations and 88 reductions. There were 12 re-registrations, meaning the same shares were recorded under a new name rather than traded.
- The largest clean increase was in SCMA, where Elang Mahkota Teknologi TBK, PT rose +12.18 pp to 86.63%. The largest clean reduction was PT. Asia Intrainvesta in NAYZ, down −32.36 pp to 24.74%.
- UNSP, TRIS and ASSA were among the registers that tightened, with concentration rising. INPS, NAYZ, DOOH and LUCY moved the other way, with concentration falling and disclosed ownership spreading more widely.
Narrative written by the Arthara insights worker from this report's own figures (run ownership-2026-08-31-v1-r4, 2 September 2026). Every figure it quotes appears in the tables below; the deterministic findings are unchanged.
What stood out this month
Re-registrations are excluded outright. Changes that pair with a block of matching size on the same stock are shown but flagged, because the data cannot establish whether the two parties are related.
PT Sinergi Internasional Investama entered DOOH
Not disclosed above 1% in Era Media Sejahtera Tbk last period. The stake now stands at 51.00%.
PT. Asia Intrainvesta trimmed NAYZ
Down from 57.10% to 24.74% in Hassana Boga Sejahtera TBK. The stake now sits below 25%.
Saiko Consultancy Pte. Ltd. entered NAYZ
Not disclosed above 1% in Hassana Boga Sejahtera TBK last period. The stake now stands at 29.41%.
PT. Prambanan Investasi Sukses trimmed DOOH
Down from 66.09% to 15.09% in Era Media Sejahtera Tbk. The stake now sits below 20%. A block of the same size moved on this stock in the same period. KSEI data does not record links between shareholders, so this could be a transfer between related parties. It could equally be two unrelated trades that happen to match.
PT Delta Wibawa Bersama trimmed LUCY
Down from 34.42% to 19.42% in Lima Dua Lima Tiga Tbk. The stake now sits below 20%.
Unbounded Opportunities Fund SPC entered UNSP
Not disclosed above 1% in Bakrie Sumatera Plantations Tbk last period. The stake now stands at 17.68%.
Daya Adicipta Mustika, PT entered ASSA
Not disclosed above 1% in Adi Sarana Armada Tbk last period. The stake now stands at 17.65%.
Dedie Suherlan added to TRIS
Up from 16.14% to 27.28% in Trisula International Tbk. Crossing 20% changes what this holder can do and what it must disclose.
Stock stories
The tickers where the month actually happened, told one at a time: who moved, from where to where, and why it matters for the register. Every figure comes from the tables in this report.
UNSP: a new 55.64% holder tightens the register
UNSP saw Poseidon Corporate Services Ltd enter with 55.64%, while Unbounded Opportunities Fund SPC entered with 17.68%. PT Bakrie Capital Indonesia fell from 17.82% to 5.21%, and Ernawati Ali fell from 10.96% to 1.61%. UNSP's concentration score, a measure of how concentrated disclosed stakes are, rose from 24 to 55 as disclosed holders fell from 12 to 9. Watch whether the 124.1 pp of movement across 16 changed positions settles into a more stable register.
What to watch: Follow whether UNSP's newly disclosed large positions remain in place after the heavy turnover.
DOOH: a 51.00% block changes hands on the register
In DOOH, PT. Prambanan Investasi Sukses dropped from 66.09% to 15.09%, while PT Sinergi Internasional Investama entered with 51.00%. This is a paired block: a purchase and sale of almost the same size on one stock. It may be one transfer or two unrelated trades. DOOH's concentration score fell from 63 to 54, while disclosed holders rose from 2 to 3. Watch whether either 51.00% position changes again after 103.8 pp of movement.
What to watch: Watch the 51.00% paired block and whether DOOH's broader disclosed register persists.
NAYZ: a large seller falls below 25%
PT. Asia Intrainvesta reduced its NAYZ stake from 57.10% to 24.74%, a change of −32.36 pp. Saiko Consultancy Pte. Ltd. entered NAYZ with 29.41%. The reduction took PT. Asia Intrainvesta below 25%, while the new holder is above that level. NAYZ's concentration score dropped from 56 to 46 and disclosed holders rose from 5 to 6. Watch whether the new 29.41% position becomes a lasting anchor.
What to watch: Follow the balance between Saiko Consultancy Pte. Ltd. and PT. Asia Intrainvesta in NAYZ.
LUCY: the largest disclosed stake falls below 20%
PT Delta Wibawa Bersama reduced its LUCY stake from 34.42% to 19.42%, or −15.00 pp. Reksa Dana Hpam Balanced Fund entered with 8.96%, while PT Sentosa Bersama Mitra, PT Pijar Investasi Nusantara and PT Nusantara Jaya Kulina exited disclosed ownership. The reduction put PT Delta Wibawa Bersama below 20%. LUCY's concentration score fell from 40 to 32, with 12 disclosed holders in both periods. Watch whether the fund's new stake offsets the exits.
What to watch: Watch for further changes among LUCY's disclosed holders after the lower concentration score.
ASSA: a new 17.65% stake concentrates ownership
Daya Adicipta Mustika, PT entered ASSA with 17.65%. No other large disclosed change is listed for ASSA in this period. Even so, ASSA's concentration score rose from 22 to 30 while disclosed holders fell from 14 to 12. That points to a tighter disclosed register, despite the new holder. Watch whether other holders reappear above disclosure levels.
What to watch: Follow whether ASSA's reduction from 14 to 12 disclosed holders continues.
TRIS: two stakes rise above 25%
Dedie Suherlan and Kiky Suherlan each increased their TRIS holdings from 16.14% to 27.28%, up +11.14 pp. Trisula Insan Tiara fell from 16.01% to 4.86%, while PT. Karya Dwimanunggal Sejahtera fell from 14.96% to 3.82%. The changes lifted both larger positions above 25% and raised TRIS's concentration score from 34 to 44. Watch whether the four large moves are followed by further disclosed reshuffling.
What to watch: Watch whether TRIS's concentration score remains at its higher level after 44.6 pp of movement.
INPS: an 79.02% holder trims and ownership spreads
PT Graha Inti Guna Persada reduced its INPS stake from 87.48% to 79.02%, a move of −8.46 pp. It remains the largest disclosed holder, at 79.0%. INPS's concentration score fell from 84 to 72, and disclosed holders increased from 3 to 5. The register is therefore less concentrated, although one stake remains dominant. Watch for further distribution from the largest disclosed position.
What to watch: Follow whether INPS gains more disclosed holders after its concentration score declined.
TCPI: several smaller stakes build as concentration rises
Susanti increased the TCPI stake from 1.85% to 4.53%, while CGS International Sekuritas Indonesia rose from 1.57% to 3.99%. Adi Putro increased from 1.45% to 3.31%, and OCBC Securities Private Limited exited a 2.24% stake. TCPI's concentration score rose from 57 to 60 as disclosed holders fell from 9 to 7. Susanti remains below the 5% disclosure threshold. Watch whether any of these growing positions cross that level.
What to watch: Watch whether Susanti's 4.53% TCPI holding crosses the 5% disclosure threshold.
What to watch
Next month, follow UNSP after 124.1 pp of turnover across 16 changed positions and a concentration score increase from 24 to 55. Also watch DOOH and NAYZ, where turnover reached 103.8 pp and 65.0 pp respectively.
Conditions that may not have finished playing out: registers that are tightening, positions parked just under an ownership threshold, and the issuers with the heaviest turnover. Crossing 5% brings disclosure duties, while 25% and 50% carry consequences for control, so a holder sitting just below one is worth following.
UNSP's register is tightening
Concentration score up from 24 to 55 while the number of ≥1% holders fell from 12 to 9. The largest holder now sits at 55.6%. A tightening register squeezes free float, and every later trade moves the stock further.
UNSP saw the heaviest shareholder turnover
Total absolute movement reached 124.1 pp across 16 changed positions in Bakrie Sumatera Plantations Tbk. Turnover this heavy usually means a corporate action, or a reshuffle that has not finished.
DOOH saw the heaviest shareholder turnover
Total absolute movement reached 103.8 pp across 3 changed positions in Era Media Sejahtera Tbk. Turnover this heavy usually means a corporate action, or a reshuffle that has not finished.
Ownership mix is shifting toward corporates
Corporates rose 0.478 pp while investment institutions fell 0.510 pp as a share of all scripless shares. Mix shifts move slowly. A direction that holds for several periods carries more weight than a single month.
Sector rotation: into basic materials, out of consumer defensive
Across positions held in both periods, basic materials gained 2.6 pp over 90 issuers while consumer defensive shed 72.0 pp over 121. Sector rotation moves slowly. A direction that holds for several periods carries more weight than a single month.
INPS's ownership is spreading out
Concentration score down from 84 to 72 with the number of ≥1% holders rising from 3 to 5. A widening free float usually improves liquidity.
Susanti is approaching the 5% threshold in TCPI
Now at 4.53% in Transcoal Pacific Tbk after adding +2.68 pp, which leaves 0.47 pp to go.
Morgan Stanley and Co International PLC is approaching the 5% threshold in GOTO
Now at 4.57% in Goto Gojek Tokopedia Tbk after adding +3.32 pp, which leaves 0.43 pp to go.
Investor classification drift
Share-count weighted ownership shifted toward Corporates, up +0.478 pp, and Individuals, up +0.186 pp. Investment institutions fell −0.510 pp, Banks & custodians fell −0.112 pp, and Government & SOEs fell −0.038 pp. The classification dates are aligned with the shareholding dates, so the comparison uses matching periods.
KSEI sorts every scripless holder into one of 36 classes. The shifts below are measured as a share of all scripless shares across issuers present at both dates, so they show which kind of owner is arriving and leaving, not just which names moved.
Investment institutions−0.510 pp
Corporates+0.478 pp
Individuals+0.186 pp
Banks & custodians−0.112 pp
Government & SOEs−0.038 pp
Largest absolute shifts
| Investor class | Previous | Current | Change |
|---|---|---|---|
| Corporate | 38.253% | 38.779% | +0.526 pp |
| Exchange-Traded Funds | 1.072% | 0.777% | −0.296 pp |
| Investment Advisors | 4.778% | 5.047% | +0.269 pp |
| Individual | 21.805% | 21.991% | +0.186 pp |
| Private Equity | 5.774% | 5.626% | −0.148 pp |
| Pension Funds | 1.373% | 1.237% | −0.137 pp |
| Trustee Bank | 1.190% | 1.061% | −0.129 pp |
| Mutual Funds | 4.455% | 4.328% | −0.127 pp |
Largest relative shifts
Small classes that moved a lot in their own terms. A class going from 0.10% to 0.15% has swung 50%, yet is almost invisible on an absolute ranking.
| Investor class | Previous | Current | Relative change |
|---|---|---|---|
| Exchange-Traded Funds | 1.072% | 0.777% | −27.6% |
| Brokerage Firms | 0.085% | 0.104% | +22.4% |
| Investment Manager | 0.646% | 0.520% | −19.3% |
| Central Bank | 0.271% | 0.239% | −11.8% |
| Trustee Bank | 1.190% | 1.061% | −10.8% |
| Pension Funds | 1.373% | 1.237% | −10.0% |
Net direction by holder classification
Sums the percentage-point change across positions held in both periods. It shows which kinds of holder added or sold, not the value of what they traded.
| Classification | Positions | Holders | Average | Foreign | Net change |
|---|---|---|---|---|---|
| Individual | 2545 | 2120 | 6.01% | 6% | +10.7 pp |
| Corporate | 2285 | 1823 | 18.58% | 17% | −159.9 pp |
| Mutual Funds | 293 | 126 | 2.57% | 33% | +3.0 pp |
| Private Bank | 241 | 39 | 6.64% | 96% | −2.5 pp |
| Securities Company | 239 | 60 | 4.84% | 46% | −5.7 pp |
| Investment Advisors | 238 | 161 | 9.28% | 56% | −13.4 pp |
| (unclassified) | 223 | 211 | 18.65% | 1% | 0.0 pp |
| Private Equity | 202 | 164 | 16.78% | 53% | +10.5 pp |
| Insurance | 150 | 43 | 6.12% | 7% | +17.6 pp |
| Firm | 149 | 110 | 15.00% | 21% | −0.3 pp |
| Bank | 103 | 40 | 13.00% | 75% | −0.4 pp |
| State Owned Enterprises | 79 | 24 | 22.23% | 4% | +8.5 pp |
Weighted by share count, not by value, and dated to the same periods as the shareholding data.
Sector rotation
Basic Materials gained +2.6 pp across 90 issuers, while Consumer Defensive lost −72.0 pp across 121 issuers. Foreign participation counts positions, not value: Consumer Defensive recorded 16 entrants and 30 exits, while Utilities recorded 1 entrant and 3 exits. Utilities' foreign participation rose from 18.3% to 19.5%.
Aggregate change by IDX sector. Net change sums movement across positions held in both periods, so it describes accumulation or distribution inside a sector's existing register. It says nothing about how big the sector is. Entries and exits are counted separately, because a name arriving is not the same as an existing holder adding.
Turnover sums all absolute movement in a sector, so large sectors always lead it purely on issuer count. Per issuer divides that by the number of issuers, and it is the column that can be compared across sectors.
| Sector | Issuers | Net change | In | Out | Turnover | Per issuer | Foreign |
|---|---|---|---|---|---|---|---|
| (Unclassified) | 55 | +19.8 pp | 5 | 23 | 104.4 pp | 1.9 pp | 16.3% |
| Basic Materials | 90 | +2.6 pp | 13 | 14 | 132.3 pp | 1.5 pp | 25.1% |
| Technology | 38 | +2.4 pp | 6 | 5 | 34.2 pp | 0.9 pp | 18.6% |
| Financial Services | 103 | +1.6 pp | 8 | 10 | 61.1 pp | 0.6 pp | 27.5% |
| Healthcare | 40 | +1.2 pp | 7 | 6 | 50.5 pp | 1.3 pp | 28.9% |
| Utilities | 14 | −0.4 pp | 1 | 3 | 9.9 pp | 0.7 pp | 19.5% |
| Energy | 57 | −3.2 pp | 6 | 8 | 47.2 pp | 0.8 pp | 22.1% |
| Real Estate | 88 | −8.9 pp | 12 | 11 | 54.7 pp | 0.6 pp | 14.2% |
| Industrials | 163 | −11.6 pp | 28 | 32 | 159.7 pp | 1.0 pp | 20.4% |
| Consumer Cyclical | 146 | −18.3 pp | 21 | 20 | 192.4 pp | 1.3 pp | 21.7% |
| Communication Services | 46 | −49.5 pp | 8 | 5 | 170.1 pp | 3.7 pp | 35.0% |
| Consumer Defensive | 121 | −72.0 pp | 16 | 30 | 295.8 pp | 2.4 pp | 23.6% |
Foreign participation shift
The share of each sector's ≥1% positions held by foreign investors. It counts positions, not value, so it tracks foreign names arriving and leaving and says nothing about how much money moved. Only sectors that shifted at least a point.
| Sector | Previous | Current | Change |
|---|---|---|---|
| Utilities | 18.3% | 19.5% | +1.2 pp |
| Consumer Defensive | 22.6% | 23.6% | +1.0 pp |
Supporting data
Changes of at least 0.5 percentage points, with re-registrations excluded. Rows markedpaired block are still shown, because their status is unresolved. The note below explains why.
Largest increases
| Investor | Issuer | Previous | Current | Change | Nature |
|---|---|---|---|---|---|
| Elang Mahkota Teknologi TBK, PT | SCMASurya Citra Media Tbk | 74.45% | 86.63% | +12.18 pp | Clean |
| Dedie Suherlan | TRISTrisula International Tbk | 16.14% | 27.28% | +11.14 pp | Clean |
| Kiky Suherlan | TRISTrisula International Tbk | 16.14% | 27.28% | +11.14 pp | Clean |
| Bakrie Metal Industries, PT | VKTRVKTR Teknologi Mobilitas Tbk | 14.20% | 21.06% | +6.86 pp | Clean |
| PT Deli Indonesia Raya | SINISingaraja Putra Tbk | 2.49% | 7.48% | +4.99 pp | Clean |
| PT. Goldman Investindo Sedaya | IBOSIndo Boga Sukses Tbk | 42.60% | 47.56% | +4.96 pp | Paired block |
| PT Softbank Ventura Indonesia | NANONanotech Indonesia Global Tbk | 5.11% | 10.01% | +4.90 pp | Clean |
| PT. Karya Pacific Investama | IATAKarya Pacific Energy Tbk | 55.50% | 60.35% | +4.85 pp | Paired block |
| PT Budi Delta Swakarya | BUDIBudi Starch & Sweetener Tbk | 33.06% | 37.59% | +4.53 pp | Paired block |
| PT. Asuransi Jiwa IFG | SMRUSMR Utama Tbk | 9.89% | 14.26% | +4.37 pp | Clean |
| PT. Asuransi Jiwa IFG | IIKPInti Agri Resources Tbk | 9.51% | 13.60% | +4.09 pp | Clean |
| PT. Asuransi Jiwa IFG | LCGPEureka Prima Jakarta Tbk | 4.68% | 8.74% | +4.06 pp | Clean |
Largest reductions
| Investor | Issuer | Previous | Current | Change | Nature |
|---|---|---|---|---|---|
| PT. Prambanan Investasi Sukses | DOOHEra Media Sejahtera Tbk | 66.09% | 15.09% | −51.00 pp | Paired block |
| PT. Asia Intrainvesta | NAYZHassana Boga Sejahtera TBK | 57.10% | 24.74% | −32.36 pp | Clean |
| PT Delta Wibawa Bersama | LUCYLima Dua Lima Tiga Tbk | 34.42% | 19.42% | −15.00 pp | Clean |
| PT Samuel Tumbuh Bersama | NSSSNusantara Sawit Sejahtera Tbk | 16.78% | 4.11% | −12.67 pp | Clean |
| PT Bakrie Capital Indonesia | UNSPBakrie Sumatera Plantations Tbk | 17.82% | 5.21% | −12.61 pp | Clean |
| Trisula Insan Tiara | TRISTrisula International Tbk | 16.01% | 4.86% | −11.15 pp | Clean |
| PT. Karya Dwimanunggal Sejahtera | TRISTrisula International Tbk | 14.96% | 3.82% | −11.14 pp | Clean |
| Ernawati Ali | UNSPBakrie Sumatera Plantations Tbk | 10.96% | 1.61% | −9.35 pp | Clean |
| Nextier Datamate Center PT | MGLVNexai Digital Infrastruktur Tbk | 75.78% | 67.08% | −8.70 pp | Clean |
| PT Graha Inti Guna Persada | INPSIndah Prakasa Sentosa Tbk | 87.48% | 79.02% | −8.46 pp | Clean |
| Stefanie Djajali | UNSPBakrie Sumatera Plantations Tbk | 9.21% | 1.35% | −7.86 pp | Clean |
| Nanotech Investama Sedaya, PT | NANONanotech Indonesia Global Tbk | 47.50% | 40.00% | −7.50 pp | Clean |
How these figures are filtered
Some movement in the raw data does not reflect a change of ownership at all. This report treats each kind differently, according to how conclusive the evidence is.
- 12 re-registration pairs are excluded outright: an identical share count reappearing under a different registered name, which is conclusively not a trade. That includes 13 “new” names and 13 “departing” ones.
- 10 changes pair with a block of matching size on the same stock but are shown with a flag. KSEI data carries no relationship between shareholders, so a matching size alone does not prove the two are connected. It may be a transfer, or two unrelated trades that happen to line up.
- 6 arrivals and departures pair off against a block of almost the same size on the same stock, and are shown with a flag. The share counts are not identical, so the re-registration test does not catch them, but one block changing hands is the likeliest explanation.
- 0 issuers appear for the first time this period and are excluded entirely. A new listing discloses its whole register at once, which would otherwise read as a wave of fresh entrants and inflate turnover.
How to read this report
A change in ownership does not always mean a market trade. Custodian migrations, corporate actions and reporting updates can all move the record without any shares changing hands. Re-registration requires an identical share count between the departing and arriving name, which is strong enough to exclude. Paired blockonly matches the size of a change against another block on the same stock; because KSEI data carries no relationship between shareholders, that flag signals uncertainty. It is not a conclusion that the parties are affiliated. Verify material findings against official disclosures before making any investment decision.