A market-wide jump in Japanese sealed Pokémon box resale prices in April 2026, about +60% in a month, then a fall of about 18% from peak by October

How it’s built

1. Took monthly flea-market resale prices for 15 Japanese box sets from PRICE BASE, a Japanese card reseller.
2. Measured the March-to-April 2026 change for seven sets: median +60%, range +28% to +86%.
3. Found each set’s peak month (11 of 15 peaked in April or May) and the fall from peak to the latest month: median −18%.

What we assumed

• Flea-market sold prices represent the resale market.It is a reseller’s survey of sold listings; the research has no other monthly Japanese series.

Sanity check

The cause of the jump is not established. Boxes still resold at a median 2.8 times list in September–October 2026, so the fall left prices high.

Where it comes from

Our calculation from other figures in the trainer’s notes:

• EstimateFlea market price step Mar to Apr 2026, March 2026 to April 20261.51 ratio
• EstimateSealed box decline from 2026 peak, April 2026 peak 68,000円 -> October 2026 49,500円

Where it’s used

• ProfileCollector and resale market