Indonesia's official foreign exchange reserves rose to $146.8 billion at the end of October from $146.3 billion a month earlier, Bank Indonesia said, as government borrowing abroad and tax receipts more than made up for the dollars the central bank spent defending the rupiah.

The figure matters for anyone holding rupiah assets. The currency has been trading close to its weakest level on record, and the size of the reserve pile is the clearest gauge of how long Bank Indonesia can keep leaning against the market. October's small gain suggests the central bank has so far been able to intervene without running its buffer down.

What moved Bank Indonesia's reserves

In its release on Friday, Nov. 6, Bank Indonesia attributed the increase mainly to withdrawals of government foreign loans and to tax and services receipts. Repayments of maturing government external debt and the bank's own rupiah stabilization operations pulled in the other direction. The central bank tied those operations to what it described as persistently high uncertainty in global financial markets.

The reserves were equivalent to 5.3 months of imports, or 5.2 months of imports plus government external debt service, the bank said. Both measures sit well above the international adequacy yardstick of roughly three months of imports.

Ramdan Denny Prakoso, executive director of the bank's communication department, said in the release that the central bank expects the external sector to remain resilient, backed by adequate reserves, foreign capital inflows and investor confidence in Indonesia's economic outlook. Bank Indonesia also said it would strengthen coordination with the government.

According to Trading Economics, October's total was the highest since March. The path through the year has been uneven. Reserves climbed to $146.5 billion in August from $145.3 billion in July, then slipped to $146.3 billion in September, when Bank Indonesia cited the same two drains of debt repayments and currency defense, its September release showed.

The composition of October's gain is worth noting. It came largely from the government's side of the ledger, through loan drawdowns and revenue, rather than from a sustained return of portfolio money into Indonesian stocks and bonds. That leaves the cushion sensitive to the timing of state borrowing and to the government's foreign debt calendar.

Rupiah stays near record low

The reserve figures arrived during a difficult stretch for the currency. The rupiah traded around 18,100 per dollar on Monday, Nov. 9, in a narrow range held since the previous week, according to Trading Economics. That is close to the record low it reached earlier this month, when Bank Indonesia stepped up intervention in the currency market.

Trading Economics said a firmer dollar weighed on the rupiah after stronger-than-expected U.S. jobs data added to bets on further Federal Reserve tightening. Higher oil prices are another strain: Indonesia is a net oil importer, so costlier crude both raises demand for dollars and squeezes the state budget. Domestic political tension over a wiretapping case involving senior police officers also hung over the market, the same report said.

Trade has been a source of support. Indonesia ran a cumulative trade surplus of $10.61 billion from January to September, according to Trade Ministry figures cited by Kabar Bursa, as a non-oil surplus of $34.21 billion outweighed a $23.60 billion deficit in oil and gas. The September surplus alone was $3.36 billion, slightly smaller than August's $3.55 billion.

MSCI review and the next tests

Equity investors have a separate reason to watch the currency. MSCI's November index review was due this week, and the index provider's final decision on Indonesia's market classification is expected by June 2027, Trading Economics noted. A weaker rupiah reduces dollar returns for foreign holders of Jakarta-listed shares and has added to pressure on a market already hit by outflows tied to the classification debate.

For Bank Indonesia, the question is whether it can keep the rupiah orderly without a visible drop in reserves. At 5.3 months of import cover, the buffer is comfortably above the benchmark, but the September dip showed that heavy intervention and debt repayments can erase a month's inflows quickly.

The next reading on the reserves is due in early December, when Bank Indonesia publishes the November figures. Before that, the central bank's board meets for its monthly policy decision, and investors will watch whether it signals further steps to support the currency.