MXN/JPY to 8.61: the survey-peso carry case

Mexican peso/Japanese yen (MXN/JPY) reaches 8.61 by December 18, 2026 in the base case, 8.75 in the bull case and 8.33 in the bear case. The figure is the Banco de México (Banxico) October survey median for the year-end peso, converted at the November 3 European Central Bank dollar-yen reference.

The European Central Bank (ECB) reference rates for November 3, 2026 fix the cross at 8.5115. That print sits 2.34% above the October 30 low of 8.3167 and 9.66% below the August 28 high of 9.4219. Dividing the implied 158.29 yen per dollar by the survey median of 18.39 produces 8.6073, which rounds to 8.61. Four signals below would retire that level before December 18, 2026.

Key levels

• Mexican peso/Japanese yen (MXN/JPY): 8.5115 on the November 3, 2026 ECB cross.
• Base case target: 8.61 by December 18, 2026, from 158.29 divided by the 18.39 median.
• Bull case target: 8.75, the 18.10 first quartile at an unchanged 158.29.
• Bear case target: 8.33, the 19.00 survey maximum at that same yen leg.
• Major support: 8.3167, the October 30, 2026 ECB cross.
• Major resistance: 8.7872, the October 8, 2026 ECB cross.
• Invalidation level: an ECB reference fix below 8.3167.

Methodology, sources and the window in use

The spot is the ECB euro reference cross for November 3, 2026: 176.9500 yen per euro divided by 20.7896 pesos per euro equals 8.5115, and the same file implies 158.29 yen per dollar and 18.5970 pesos per dollar. The lookback is the 64 ECB reference dates from August 6, 2026 through November 3, 2026. Banxico held the overnight target at 6.50% on September 24, in a unanimous vote in the minutes published on October 8. The Bank of Japan (BOJ) kept the call rate at around 1.25% on October 30, eight to one, in its Statement on Monetary Policy. Peso forecasts are the October survey of 40 groups, collected from October 19 to October 29 and released on November 3 (survey note). Dates come from Banxico's 2026 announcement calendar and the BOJ release schedule of October 30.

Related:GBP/SGD to 1.7172: the Bank of England policy gap

Where the reference cross sits after the October low

From August 28 to October 30, dollar-yen eased from 159.68 to 157.25 while the peso weakened from 16.9481 to 18.9077, so the peso produced most of the 1.1052 yen drop, from 9.4219 to 8.3167.

Sources: ECB euro reference rates supply 64 fixes from August 6 to November 3, 2026. MXN/JPY extremes fall on August 28 and October 30, USD/JPY extremes on September 1 and September 9, and USD/MXN extremes on October 30 and August 21.

MXN/JPY is the number of yen one peso buys. On the November 3 ECB rates, 176.9500 yen per euro divided by 20.7896 pesos per euro is 8.5115, and the same fix implies 158.29 yen per dollar against 18.5970 pesos per dollar. Across the 64 dates from August 6 to November 3 the cross peaked at 9.4219 on August 28 and bottomed at 8.3167 on October 30, a 9.66% fall from the high, with a 2.34% bounce off the low. The Bank of Japan's daily foreign-exchange list runs through November 2, so the ECB file is the latest same-day official pair, and a later dealing quote can differ from 8.5115. In the October survey the end-2026 policy-rate median is 6.50% for 2026 and for 2027, headline inflation is 3.88% then 3.85%, and the 2026 growth median is 1.50%.

Why 8.61 is a survey peso with the yen held still

The base case freezes the yen and moves only the peso. Banxico's overnight target is 6.50% and the Bank of Japan's call rate is around 1.25%, a gap of 525 basis points. The horizon is December 18, 2026, the second day of the next BOJ meeting, because the October statement was released on the second day. The yen stays at the November 3 ECB implication of 158.29 per dollar, the peso moves to the end-2026 median of 18.39, and 158.29 divided by 18.39 is 8.6073, published as 8.61.

The bull case, 18.10 pesos per dollar at 158.29, is a ratio of 8.7452 published as 8.75. The bear case, the survey maximum of 19.00, is 8.3309 published as 8.33, about 14 pips above the October 30 low. The October 30 statement set exchange-traded fund sales at about 860 billion yen a year on a book-value basis. Earlier notes on the forex desk, the Singapore dollar/yen note and the Canadian dollar/yen note covered an October meeting that has now passed.

"We saw the need to scrutinise a bit more economic and price risks, as well as financial conditions. But underlying inflation has reached levels consistent with our price target. Financial conditions remain accommodative. There are various upside risks. We must therefore be vigilant to the risk of inflation overshooting our target."

— Kazuo Ueda, governor, Bank of Japan (Reuters, October 30, 2026)

Governor Ueda called financial conditions still accommodative at around 1.25%, while flagging a hike risk on December 18. Hajime Takata's proposal of around 1.5% lost eight to one.

What a frozen yen leaves out of the 8.61 case

The limit of the 8.61 case is the frozen yen, because the peso is the only leg that moves. The strongest yen in the ECB window was September 9, 2026, at 153.27 per dollar, and pairing that rate with the survey median of 18.39 puts the cross at 8.3344, while pairing 153.27 with the survey maximum of 19.00 puts it at 8.0668, through the October 30 low of 8.3167. A December move back towards that September 9 yen reference would break 8.61 even if the peso landed on 18.39. Respondents filed from October 19 to October 29, and the November monthly median of 18.43 implies 8.5886 at 158.29, about two pips from 8.61, which is a check only while the yen stays put. The euro/yen vanishing-carry note is the analogue for a high-yield cross once the yen leg reprices.

"En la última minuta de política monetaria, 3 de los 5 miembros de la Junta de Gobierno mostraron sesgo a volver a recortar la tasa de interés, lo que implicaría un menor diferencial de tasas de interés entre México y EEUU."

— Gabriela Siller Pagaza, director of economic analysis, Grupo Financiero Base (post on X, October 21, 2026)

Siller's sentence is her reading of the October 8 minutes, beside a September 24 vote that was unanimous for 6.50%. A cut on November 5 would narrow the 525 basis point gap, the condition in the dollar/zloty note on a central-bank hold.

What would invalidate the base case

The base case of 8.61 breaks if any one of these four signals prints, because each one removes a leg the arithmetic uses.

• Banxico sets the overnight target below 6.50% on November 5, 2026, or the next end-2026 rate median sits below 6.50%. The carry case starts from a 6.50% peso rate, and a cut would shrink the 525 basis point gap before the BOJ has met.
• The BOJ sets the call rate at around 1.5% on December 18, 2026. That is the level Hajime Takata proposed on October 30, and a 25 basis point rise would reprice the yen leg held at 158.29.
• The ECB reference cross fixes below 8.3167. That October 30 print is the window low, and a fix beneath it would pass the 8.3309 cross implied by the weakest year-end peso forecast at an unchanged yen.
• A later Banxico survey lifts the end-2026 median above 19.00 pesos per dollar. At 158.29 yen per dollar, a median above 19.00 implies a cross below 8.3309 and removes the anchor under 8.61.

What to watch before December 18

November 5, 2026 brings Banxico's announcement at 13:00 Central Standard Time, minutes on November 19 and the quarterly report on November 26. The same BOJ schedule lists the September 17 and 18 minutes that morning at 8:50, the October 29-30 Summary of Opinions on November 10 at 8:50, and Governor Ueda's Washington speech for November 6. Banxico announces again on December 17, and the BOJ meets on December 17 and 18. The levels into that date are 8.3167 and 8.7872.

TL;DR

MXN/JPY reaches 8.61 by December 18, 2026 in the base case, 8.75 in the bull case and 8.33 in the bear case. The November 3, 2026 ECB reference cross is 8.5115, from 176.9500 yen per euro and 20.7896 pesos per euro. Dividing that day's implied 158.29 yen per dollar by Banxico's median of 18.39 gives 8.6073, which rounds to 8.61, with the policy gap at 525 basis points. An ECB fix below the October 30 low of 8.3167 invalidates the recovery.

FAQ

What is the MXN/JPY base case, and where does 8.61 come from?

The base case is 8.61 yen per peso by December 18, 2026. Banxico's median of 18.39 pesos per dollar, divided into the November 3 ECB rate of 158.29 yen per dollar, produces an unrounded ratio of 8.6073. The bull case of 8.75 uses the first quartile of 18.10, the bear case of 8.33 uses the survey maximum of 19.00, and the spot is the ECB cross of 8.5115.

When do Banco de México and the Bank of Japan next announce?

Banco de México's calendar places the next announcement on November 5, 2026 and the following one on December 17, at 13:00 Central Standard Time on Thursdays, with November minutes on November 19. The Bank of Japan's October 30 schedule lists the next meeting on December 17 and 18, 2026. December 18 is the horizon because the October statement was released on the second day.

How wide is the rate gap under the cross?

Banco de México's overnight target is 6.50%, held unanimously on September 24, 2026. The Bank of Japan's October 30 guideline, passed eight to one, keeps the call rate at around 1.25%. The gap is 525 basis points. The October survey median keeps the Mexican rate at 6.50% through the end of 2027. Hajime Takata's proposal of around 1.5% on October 30 was defeated.

Which print would invalidate the recovery to 8.61?

An ECB reference fix below 8.3167, the October 30 low of the August 6 to November 3 window, would invalidate the recovery to 8.61. A Banxico overnight target below 6.50% on November 5, or a Bank of Japan call rate around 1.5% on December 18, would also retire it, because each change moves a leg held fixed at the November 3 ECB rates.

This article is informational analysis only and is not financial, investment or trading advice, foreign-exchange markets can lose substantial value rapidly, leveraged products carry total-loss risk that may exceed posted margin, and readers should consult a regulated financial adviser before any decision because past correlations can fail.