Why exchange rates change all day in 2026: a 3-minute primer
⚡ 30-Second Answer: FX rates move due to ①central bank rate gaps (Fed vs BoJ), ②trade balance, ③geopolitical risk, ④speculative capital flows, and ⑤real demand (travel + trade settlement). 1-3% daily moves aren't rare. Travelers should plan for ±5-10% swings over a 2-3 month booking window — use mid-rate-tracking services like Wise/Revolut to hedge.
Quick Reference Value Key drivers Rate gaps, trade, geopolitics Typical daily move 0.3-1.0% Big move days 1-3% (central bank events) 2-3 month range ±5-10% Hedge Wise/Revolut tracks mid Last verified June 2026
Exchange rates change continuously during forex market hours (Sunday evening UTC through Friday afternoon UTC) because the global forex market trades 24 hours, with banks and institutions constantly updating bid/ask prices based on supply, demand, and news. Retail Japanese exchange shops typically update 1–3 times per day, so the rate you see at a shop may lag the live mid-market by hours.
TL;DR
- Forex trades 24/5 — Sunday evening through Friday afternoon UTC.
- Retail shops update 1–3 times daily — they're not real-time.
- The shop rate is essentially "morning's mid-market" + a spread — pre-built into the displayed number.
- Best time to exchange: late morning when shops have updated for the day.
How does the global forex market work?
Three things drive continuous price changes:
1. Supply and demand
Every minute, dozens of major banks make currency trades worth billions of dollars. Those trades shift the bid/ask prices that determine the mid-market rate.
2. News and economic data
Interest rate announcements (BOJ, Fed, ECB), GDP releases, unemployment numbers, geopolitical events — each causes immediate rate movements.
3. Carry trade and macro positioning
Hedge funds and institutions take long-term currency positions; their entry/exit moves the market.
The result: USD/JPY can move 0.3–1.5% in a single day, with some weeks seeing 3–5% movements.
How fast do retail shops update?
| Shop type | Update frequency |
|---|---|
| Wise / Revolut | Real-time at transaction |
| Major Japanese ATM (7-Eleven Seven Bank) | Real-time via card network |
| Dedicated Tokyo exchange shop | 1–3 times daily |
| Small pawn-shop FX windows | Once daily (morning) |
| Hotel front desks | Once daily or less |
The lag means: the rate you see at a small Tokyo shop in the afternoon may reflect the morning's mid-market, not the current afternoon's. If the rate has moved overnight or during the day, the shop rate may be slightly stale.