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Why exchange rates change a US benchmark expressed in SGD

Follow the three-step conversion from SGD to USD and back, and see how currency movements can change a money-value comparison.

CapsWindowPublished:
USDExchange rate
Three-step diagram for a SGD amount: convert to USD, apply a US index ratio, then convert back.

Why is the US index alone not enough?

An amount recorded in SGD and a US index do not share a currency basis. CapsWindow first translates the starting amount into USD, applies the selected US M2 or CPI ratio, and converts the resulting amount back at the ending rate. Therefore the US index can rise while the answer in SGD changes by more or less. That difference includes the exchange-rate effect.

Federal Reserve · H.10: exchange-rate quotation

What is the three-step formula?

Let A be the starting amount, E0 and E1 the starting and ending quotes in SGD per USD, and U0 and U1 the US index values. The result is (A / E0) × (U1 / U0) × E1. In a hypothetical example, A=1,000, E0=10, E1=12 and U1/U0=1.10. The steps are 100 USD, then 110 USD, then 1,320 SGD. The rates are assumptions, not actual quotes for SGD.

FromFormulaTo
1000 SGD1000 / 10100 USD
100 USD100 × 1.10110 USD
110 USD110 × 121320 SGD

Which details can distort the comparison?

When E rises, one USD costs more SGD: the local currency has weakened against USD. If your source instead quotes USD per local unit, invert the quote before applying this formula. Also align the months. Combining monthly averages is a period comparison, not a reconstruction of an exact daily conversion. Bank spreads, fees and taxes are outside this calculation.

SGD · Data & methodology

Local M2: DEMO · Synthetic data, not official statistics
Latest observation: 2026-08
Unit: SGD

Data & methodology →

How should you compare the four results?

Compare local M2, local CPI, US M2 converted to SGD, and US CPI converted to SGD over the same available period. The US-derived answers do not measure local consumer prices. Read the USD component and the exchange-rate contribution separately before drawing a conclusion. Missing data should lead to an unavailable result, not an invented exchange rate.

Compare local and US benchmarks →

Questions & answers

Does a larger converted result mean the US index rose faster?

Not necessarily. A change in SGD per USD can amplify or offset the US index change. Inspect both ratios.

Is this the return from holding dollars?

No. It is a statistical benchmark calculation. It does not model interest earned, trade timing, spreads, fees or taxes.

Source

  1. CapsWindow · Data & methodology ↗
  2. Federal Reserve · H.10: exchange-rate quotation ↗

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