ASSETCASTING

What followed a 5% one-month fall in USD/KRW?

won per 1 dollar · New downward crossing of -5% over the preceding 21 valid observations → next 21 valid observations

Total 16 · Completed 15 · Ongoing 1 · Excluded 0

Last observed 2026-09-04 · Updated 2026-10-09

Positive / completed cases5 / 15Negative 10 · Flat 0
Return Median-0.9%Mean -0.7%
Completed outcome range-5.3% ~ +6.3%Minimum ~ maximum

Same conditions, different outcomes

Positive and negative outcomes are compared against 0%. Ongoing and excluded cases are not included in the statistics. Open a case to explore its context.

2026.09.04 -5% condition confirmedOngoing · 2026-09-04—

Observed 2026-09-04 → End unconfirmed · As of 2026-10-02

Starting observation
2026-09-04 · 1,346.51 KRW/USD
Sample end
2026-10-02 · Follow-up observation window incomplete
Change over the preceding 21 valid observations
-5.4158% (2026-08-06 → 2026-09-04)
Condition threshold
New crossing of the -5% threshold · No overlap with the preceding case’s follow-up window

The condition was confirmed on 2026-09-04, but the specified follow-up observation window had not ended as of 2026-10-02. The final change is not calculated, and the case is excluded from completed-case statistics.

2026.07.24 -5% condition confirmedCompleted · 2026-07-24-5.3%

Observed 2026-07-24 → 2026-08-24 · As of 2026-10-02

Starting observation
2026-07-24 · 1,460.76 KRW/USD
Ending observation
2026-08-24 · 1,383.15 KRW/USD
Change over the preceding 21 valid observations
-5.301% (2026-06-24 → 2026-07-24)
Condition threshold
New crossing of the -5% threshold · No overlap with the preceding case’s follow-up window

The observed won per 1 dollar changed from 1,460.76 to 1,383.15, a spot-quote change of -5.313%. Positive values indicate dollar strength and won weakness; negative values indicate dollar weakness and won strength. This is not an investment return incorporating interest-rate differentials, carry and transaction costs, and the condition is not established as the cause of the change.

2025.05.05 -5% condition confirmedCompleted · 2025-05-05-0.8%

Observed 2025-05-05 → 2025-06-04 · As of 2026-10-02

Starting observation
2025-05-05 · 1,375.11 KRW/USD
Ending observation
2025-06-04 · 1,364.16 KRW/USD
Change over the preceding 21 valid observations
-5.6697% (2025-04-04 → 2025-05-05)
Condition threshold
New crossing of the -5% threshold · No overlap with the preceding case’s follow-up window

The observed won per 1 dollar changed from 1,375.11 to 1,364.16, a spot-quote change of -0.7963%. Positive values indicate dollar strength and won weakness; negative values indicate dollar weakness and won strength. This is not an investment return incorporating interest-rate differentials, carry and transaction costs, and the condition is not established as the cause of the change.

2022.12.21 -5% condition confirmedCompleted · 2022-12-21-3.9%

Observed 2022-12-21 → 2023-01-24 · As of 2026-10-02

Starting observation
2022-12-21 · 1,284.7 KRW/USD
Ending observation
2023-01-24 · 1,234.79 KRW/USD
Change over the preceding 21 valid observations
-5.1791% (2022-11-21 → 2022-12-21)
Condition threshold
New crossing of the -5% threshold · No overlap with the preceding case’s follow-up window

The observed won per 1 dollar changed from 1,284.7 to 1,234.79, a spot-quote change of -3.885%. Positive values indicate dollar strength and won weakness; negative values indicate dollar weakness and won strength. This is not an investment return incorporating interest-rate differentials, carry and transaction costs, and the condition is not established as the cause of the change.

2022.11.14 -5% condition confirmedCompleted · 2022-11-14-2.5%

Observed 2022-11-14 → 2022-12-14 · As of 2026-10-02

Starting observation
2022-11-14 · 1,327.38 KRW/USD
Ending observation
2022-12-14 · 1,294.79 KRW/USD
Change over the preceding 21 valid observations
-7.2022% (2022-10-13 → 2022-11-14)
Condition threshold
New crossing of the -5% threshold · No overlap with the preceding case’s follow-up window

The observed won per 1 dollar changed from 1,327.38 to 1,294.79, a spot-quote change of -2.4552%. Positive values indicate dollar strength and won weakness; negative values indicate dollar weakness and won strength. This is not an investment return incorporating interest-rate differentials, carry and transaction costs, and the condition is not established as the cause of the change.

2017.01.31 -5% condition confirmedCompleted · 2017-01-31-0.4%

Observed 2017-01-31 → 2017-03-02 · As of 2026-10-02

Starting observation
2017-01-31 · 1,151.45 KRW/USD
Ending observation
2017-03-02 · 1,146.9 KRW/USD
Change over the preceding 21 valid observations
-5.0131% (2016-12-28 → 2017-01-31)
Condition threshold
New crossing of the -5% threshold · No overlap with the preceding case’s follow-up window

The observed won per 1 dollar changed from 1,151.45 to 1,146.9, a spot-quote change of -0.3952%. Positive values indicate dollar strength and won weakness; negative values indicate dollar weakness and won strength. This is not an investment return incorporating interest-rate differentials, carry and transaction costs, and the condition is not established as the cause of the change.

2016.03.17 -5% condition confirmedCompleted · 2016-03-17-1%

Observed 2016-03-17 → 2016-04-15 · As of 2026-10-02

Starting observation
2016-03-17 · 1,155.83 KRW/USD
Ending observation
2016-04-15 · 1,144.83 KRW/USD
Change over the preceding 21 valid observations
-5.4397% (2016-02-17 → 2016-03-17)
Condition threshold
New crossing of the -5% threshold · No overlap with the preceding case’s follow-up window

The observed won per 1 dollar changed from 1,155.83 to 1,144.83, a spot-quote change of -0.9517%. Positive values indicate dollar strength and won weakness; negative values indicate dollar weakness and won strength. This is not an investment return incorporating interest-rate differentials, carry and transaction costs, and the condition is not established as the cause of the change.

2015.10.26 -5% condition confirmedCompleted · 2015-10-26+1.2%

Observed 2015-10-26 → 2015-11-25 · As of 2026-10-02

Starting observation
2015-10-26 · 1,127.47 KRW/USD
Ending observation
2015-11-25 · 1,140.67 KRW/USD
Change over the preceding 21 valid observations
-5.6889% (2015-09-24 → 2015-10-26)
Condition threshold
New crossing of the -5% threshold · No overlap with the preceding case’s follow-up window

The observed won per 1 dollar changed from 1,127.47 to 1,140.67, a spot-quote change of 1.1708%. Positive values indicate dollar strength and won weakness; negative values indicate dollar weakness and won strength. This is not an investment return incorporating interest-rate differentials, carry and transaction costs, and the condition is not established as the cause of the change.

2011.10.28 -5% condition confirmedCompleted · 2011-10-28+3.4%

Observed 2011-10-28 → 2011-11-30 · As of 2026-10-02

Starting observation
2011-10-28 · 1,102.5 KRW/USD
Ending observation
2011-11-30 · 1,140.05 KRW/USD
Change over the preceding 21 valid observations
-5.922% (2011-09-28 → 2011-10-28)
Condition threshold
New crossing of the -5% threshold · No overlap with the preceding case’s follow-up window

The observed won per 1 dollar changed from 1,102.5 to 1,140.05, a spot-quote change of 3.4059%. Positive values indicate dollar strength and won weakness; negative values indicate dollar weakness and won strength. This is not an investment return incorporating interest-rate differentials, carry and transaction costs, and the condition is not established as the cause of the change.

2010.10.06 -5% condition confirmedCompleted · 2010-10-06-0.9%

Observed 2010-10-06 → 2010-11-05 · As of 2026-10-02

Starting observation
2010-10-06 · 1,117.4 KRW/USD
Ending observation
2010-11-05 · 1,107.7 KRW/USD
Change over the preceding 21 valid observations
-5.0637% (2010-09-07 → 2010-10-06)
Condition threshold
New crossing of the -5% threshold · No overlap with the preceding case’s follow-up window

The observed won per 1 dollar changed from 1,117.4 to 1,107.7, a spot-quote change of -0.8681%. Positive values indicate dollar strength and won weakness; negative values indicate dollar weakness and won strength. This is not an investment return incorporating interest-rate differentials, carry and transaction costs, and the condition is not established as the cause of the change.

2009.09.25 -5% condition confirmedCompleted · 2009-09-25+0.5%

Observed 2009-09-25 → 2009-10-27 · As of 2026-10-02

Starting observation
2009-09-25 · 1,184.25 KRW/USD
Ending observation
2009-10-27 · 1,190 KRW/USD
Change over the preceding 21 valid observations
-5.169% (2009-08-26 → 2009-09-25)
Condition threshold
New crossing of the -5% threshold · No overlap with the preceding case’s follow-up window

The observed won per 1 dollar changed from 1,184.25 to 1,190, a spot-quote change of 0.4855%. Positive values indicate dollar strength and won weakness; negative values indicate dollar weakness and won strength. This is not an investment return incorporating interest-rate differentials, carry and transaction costs, and the condition is not established as the cause of the change.

2009.08.11 -5% condition confirmedCompleted · 2009-08-11-1.6%

Observed 2009-08-11 → 2009-09-10 · As of 2026-10-02

Starting observation
2009-08-11 · 1,242.7 KRW/USD
Ending observation
2009-09-10 · 1,223 KRW/USD
Change over the preceding 21 valid observations
-5.0649% (2009-07-13 → 2009-08-11)
Condition threshold
New crossing of the -5% threshold · No overlap with the preceding case’s follow-up window

The observed won per 1 dollar changed from 1,242.7 to 1,223, a spot-quote change of -1.5853%. Positive values indicate dollar strength and won weakness; negative values indicate dollar weakness and won strength. This is not an investment return incorporating interest-rate differentials, carry and transaction costs, and the condition is not established as the cause of the change.

2009.04.30 -5% condition confirmedCompleted · 2009-04-30-3.5%

Observed 2009-04-30 → 2009-06-01 · As of 2026-10-02

Starting observation
2009-04-30 · 1,277 KRW/USD
Ending observation
2009-06-01 · 1,232.7 KRW/USD
Change over the preceding 21 valid observations
-7.3463% (2009-04-01 → 2009-04-30)
Condition threshold
New crossing of the -5% threshold · No overlap with the preceding case’s follow-up window

The observed won per 1 dollar changed from 1,277 to 1,232.7, a spot-quote change of -3.4691%. Positive values indicate dollar strength and won weakness; negative values indicate dollar weakness and won strength. This is not an investment return incorporating interest-rate differentials, carry and transaction costs, and the condition is not established as the cause of the change.

2009.03.20 -5% condition confirmedCompleted · 2009-03-20-4.8%

Observed 2009-03-20 → 2009-04-20 · As of 2026-10-02

Starting observation
2009-03-20 · 1,396.5 KRW/USD
Ending observation
2009-04-20 · 1,330 KRW/USD
Change over the preceding 21 valid observations
-5.6865% (2009-02-19 → 2009-03-20)
Condition threshold
New crossing of the -5% threshold · No overlap with the preceding case’s follow-up window

The observed won per 1 dollar changed from 1,396.5 to 1,330, a spot-quote change of -4.7619%. Positive values indicate dollar strength and won weakness; negative values indicate dollar weakness and won strength. This is not an investment return incorporating interest-rate differentials, carry and transaction costs, and the condition is not established as the cause of the change.

2008.12.17 -5% condition confirmedCompleted · 2008-12-17+2.1%

Observed 2008-12-17 → 2009-01-20 · As of 2026-10-02

Starting observation
2008-12-17 · 1,324 KRW/USD
Ending observation
2009-01-20 · 1,351.5 KRW/USD
Change over the preceding 21 valid observations
-6.0993% (2008-11-17 → 2008-12-17)
Condition threshold
New crossing of the -5% threshold · No overlap with the preceding case’s follow-up window

The observed won per 1 dollar changed from 1,324 to 1,351.5, a spot-quote change of 2.077%. Positive values indicate dollar strength and won weakness; negative values indicate dollar weakness and won strength. This is not an investment return incorporating interest-rate differentials, carry and transaction costs, and the condition is not established as the cause of the change.

2008.11.07 -5% condition confirmedCompleted · 2008-11-07+6.3%

Observed 2008-11-07 → 2008-12-10 · As of 2026-10-02

Starting observation
2008-11-07 · 1,310 KRW/USD
Ending observation
2008-12-10 · 1,393 KRW/USD
Change over the preceding 21 valid observations
-7.4368% (2008-10-08 → 2008-11-07)
Condition threshold
New crossing of the -5% threshold · No overlap with the preceding case’s follow-up window

The observed won per 1 dollar changed from 1,310 to 1,393, a spot-quote change of 6.3359%. Positive values indicate dollar strength and won weakness; negative values indicate dollar weakness and won strength. This is not an investment return incorporating interest-rate differentials, carry and transaction costs, and the condition is not established as the cause of the change.

How to interpret this

These descriptive statistics compare how direction and magnitude differed across observed cases under the same condition. Positive values indicate dollar strength and won weakness; negative values indicate dollar weakness and won strength. A particular season or a past sharp move cannot be assumed to determine subsequent exchange rates. No comparison with unconditional changes over the full period or separate validation sample was performed, so no outperformance is claimed.

These are changes in spot exchange-rate or dollar-index quotes, not investment returns including dividends, interest, carry, transaction costs and foreign-exchange spreads. Examining multiple conditions within the same sample can produce chance findings. Thresholds are not natural economic laws, and results differ with other criteria. Follow-up windows within the same pattern do not overlap, but statistical independence is not guaranteed and cases can overlap across patterns. Federal Reserve data are published after their observation dates and may be revised, so these results do not establish real-time tradability or predictive power.

Conditions, methodology and sources

Examines valid daily observations from 2007-01-01~2026-10-02 in sequence, using 2006 data for preliminary calculations. The condition observation date is the first crossing when the change versus 21 valid observations earlier reaches -5% or lower. The same condition must not have been met on the preceding day. After selecting a case, no other case is selected from that date through the next 21 valid observations; only a new subsequent crossing is selected. All cases meeting this rule are included, without selecting by the direction of the outcome. The endpoint of the next 21 valid observations is not used to select the condition. The 21 observations represent roughly a month, not a calendar month; cases with insufficient follow-up observations remain ongoing. Source data are the Federal Reserve’s H.10 daily data. Missing status ND(-9999) is excluded without interpolation. Change is calculated as (ending observation / starting observation - 1) × 100 and stored to 8 decimal places. Quotes are won per 1 dollar, with positive values indicating dollar strength and won weakness; negative values indicate dollar weakness and won strength. Dates are source observation reference dates, not publication times or times when trading was possible. The source is revised data from the release of 2026-10-05, not a real-time investment-strategy backtest.