IDX Composite Initially Rose 1% but Ended in the Red, What Happened?
The Indonesia Composite Index (IHSG) reversed direction into the red during Wednesday’s (16/09/2026) trading, after initially gaining more than 1% at the start of the session. Foreign investor selling of large-cap banking stocks became a primary focus for the market.
According to trading data, the IHSG closed lower by 0.38% at the 6,436.85 level. This occurred despite the index reaching a position of 6,526.81, a 1.02% increase, at 0.932 WIB.
Pressure on the IHSG occurred amidst foreign investor selling, which recorded a net sell of Rp624.7 billion across the entire market. Large-cap banking stocks were the primary targets; four major bank stocks recorded a net sell accumulation of Rp344.6 billion.
Bank Mandiri (BMRI) was the banking stock most heavily sold by foreigners with a net sell of Rp238.4 billion. This was followed by Bank Central Asia (BBCA) at Rp57.9 billion, Bank Negara Indonesia (BBNI) at Rp24.2 billion, and Bank Rakyat Indonesia (BBRI) at Rp24.1 billion. Consequently, the foreign selling of these four major banks accounted for approximately 55% of the total foreign net sell in the stock market.
Financial Sector Acts as a Drag
Based on Refinitiv data, the pressure on banking stocks was in line with the weakening of the financial sector, which corrected by 0.71% during yesterday’s trading. In fact, the financial sector was one of the sectors that experienced a relatively deep decline. The technology sector corrected by 1.34%, utilities weakened by 1.82%, and real estate fell by 0.95%.
Overall, the majority of stock sectors moved in the red zone. In addition to these sectors, the industrial sector weakened by 0.46%, while cyclical consumer and non-cyclical consumer sectors each corrected by 0.14%.
On the other hand, the energy sector actually strengthened by 2.54%, becoming the sector with the highest increase. The basic materials sector also rose by 0.27%, followed by healthcare, which edged up by 0.04%. However, the strength in the energy and basic materials sectors was insufficient to offset the pressure from the financial and other sectors.
BYAN and AMMN Support IHSG
Although the IHSG ended lower, several stocks still provided a positive contribution to the index movement. Referring to Refinitiv data, PT Bayan Resources Tbk (BYAN) was the largest supporter of the IHSG, contributing an increase of 28.61 index points. BYAN shares closed at the Rp11,350 level, with a change contribution of 0.44%.
Furthermore, PT Amman Mineral Internasional Tbk (AMMN) contributed an increase of 4.48 index points, followed by PT Bank Rakyat Indonesia (Persero) Tbk (BBRI) by 3.11 points. Other stocks that supported the index included PT Dian Swastatika Sentosa Tbk (DSSA), PT Impack Pratama Industri Tbk (IMPC), PT Merdeka Copper Gold Tbk (MDKA), PT Alamtri Resources Indonesia Tbk (ADRO), PT Aneka Tambang Tbk (ANTM), PT Bumi Resources Tbk (BUMI), and PT Timah Tbk (TINS).
Conversely, the greatest pressure came from PT Sinarmas Multiartha Tbk (SMMA) with a decrease contribution of 3.54 index points. BMRI and PT Maha Properti Indonesia Tbk (MPRO) each provided a negative contribution of 2.61 points.
Thus, yesterday’s IHSG decline was not uniform. While several mining stocks continued to support the index, pressure from banking stocks and other sectors caused the IHSG to fail to maintain its early trading gains. Meanwhile, trading data showed that 456 stocks declined, 213 stocks rose, and 294 stocks remained unchanged.