IHSG vs S&P 500: 88% Return in Rupiah, Only 55% in Dollars
6 min read
Loading...
6 min read
If you have held Indonesian stocks for the last ten years, you have probably seen a chart somewhere showing the IHSG (Indonesia's main stock index) is up about 88% since 2015. That sounds decent, until you put it next to the S&P 500 (the main US stock index), which is up 235% over the exact same ten years. That is already a wide gap in an IHSG vs S&P 500 comparison. But it is not the whole story. Convert both numbers into the same currency and the gap gets bigger, not smaller.
Here is the plain comparison first, each index in its own home currency, using the last full decade of closed calendar years, 30 December 2015 to 30 December 2025 for the IHSG and 31 December 2015 to 31 December 2025 for the S&P 500.
| Index | Year-end 2015 | Year-end 2025 | 10-year price return | Annual growth rate |
|---|---|---|---|---|
| IHSG (Indonesia) | 4,593.01 | 8,646.94 | +88.3% | ~6.5%/year |
| S&P 500 (United States) | 2,043.94 | 6,845.50 | +235.0% | ~12.8%/year |
IHSG: Bisnis.com, 30 December 2015 close, and Media Indonesia, 30 December 2025 close (cross-corroborated by Kabarbursa). S&P 500: closing levels widely reported for both dates, including CNBC's 2025 year-end market wrap. Percentage changes and the annual growth rate are self-derived from these sourced, dated closing levels.
Annual growth rate here means CAGR, short for compound annual growth rate. It is the single steady yearly return that would take a starting number to an ending number over ten years, smoothing out every up year and down year in between into one number you can compare across two different markets.
The 88% and 235% figures above are both real, but they are not actually comparable the way they look, because they are measured in two different currencies. The IHSG is priced in rupiah. The S&P 500 is priced in US dollars. Over the same ten years, the rupiah itself lost value against the dollar, from roughly Rp13,795 per US dollar at the end of 2015 to Rp16,737 per US dollar at the end of 2025 (Bisnis.com, Bank Indonesia's JISDOR benchmark rate for 2015, cross-corroborated by Ajaib.co.id; Liputan6 for 2025), a depreciation of about 21.3%.
That matters because a global investor, or anyone benchmarking against a US index fund, is not going to think in rupiah. They think in dollars. Once you convert the IHSG's rupiah return into dollar terms using those two exchange rates, its 10-year return drops from +88.3% to roughly +55.2%, a figure self-derived from the sourced index levels and exchange rates above, not a separately cited statistic. The S&P 500 needs no conversion; it is already in dollars.
| Index, converted to US dollars | 10-year return |
|---|---|
| IHSG | ~+55.2% |
| S&P 500 | +235.0% |
Put both numbers in the same currency and the gap does not shrink. It grows, from a 147-point gap in local currency terms to roughly a 180-point gap once the rupiah's own decline is added on top.
Here is the part that surprises most people: the exact same exchange-rate move helps an Indonesian investor who did the opposite trade. If you had converted rupiah into dollars ten years ago, put that money into the S&P 500, and converted it back into rupiah today, your return would not be the S&P 500's own 235%. It would be higher, roughly +306%, again self-derived from the sourced index levels and exchange rates rather than a separately cited figure.
That happens because two things worked in the same direction at once: US stocks grew faster than Indonesian stocks, and the dollars from that growth converted back into more rupiah than you started with, because the rupiah had weakened in the meantime. The currency move does not cancel out between the two comparisons above. It adds to whichever side already has the stronger asset-price return, which is why the IHSG-in-dollars comparison got worse for Indonesia while the S&P-500-in-rupiah comparison got even better for a rupiah-based investor holding it.
The lesson is not "the S&P 500 always wins" or "never hold Indonesian stocks." Ten years is one specific window, and both markets have had very different decades before this one. The lesson is narrower and more useful: whenever you compare a return in rupiah to a return in another currency, ask which currency the comparison is actually being made in, because the answer can move the result by tens of percentage points in either direction. This same currency effect is exactly what showed up in our comparison of the IHSG against its Southeast Asian neighbors, where converting to dollars made Indonesia's 2026 underperformance look worse, not better, once the rupiah's own move was added on top.
NetWort's Market page has separate heatmaps for the US and IDX markets, so you can see how today's move in each one compares without waiting for a headline. If you track a US index fund like the SPDR S&P 500 ETF Trust (SPY), pull up its own price history there before assuming today's move looks anything like the ten-year story above.