Collectors bring stock market instincts to card charts and get burned, because a card market has a few sales a week and a stock has millions. The chart of a One Piece card has to be read differently. These are the four things to check, in the order they matter.
The four checks
- The range, not the line. On a thin market the meaningful number is the band the price has stayed inside for 60 to 90 days. A move inside the band is noise; a move that leaves the band is news.
- The steps. Card prices move in steps, not slopes: a flat month, then a jump when the last cheap copies sell, then another flat month. A chart with three steps up in a year is a strong card. A chart with one spike and a slide is one sale.
- The spike test. If a single point sits far above its neighbours and the next point is back in the band, it was one sale. Do not buy the spike and do not sell the dip after it.
- Volume in the background. A card with hundreds of sales a year has a chart you can trust point by point. A card with ten sales a year has a chart that is a rumor between the points.
On a card chart, the band is the price. The line is just where the band was last measured.

Your vault updates with daily prices; Mugi Vision checks a card in seconds.
Two charts, side by side
Boa Hancock Manga OP07-051 is a high volume chart: hundreds of sales a year, clear steps, a band you can trade against. Luffy Red Manga OP13-118 is a low volume chart: a few sales a month, a $12,900 spike in July and an $8,900 band since. Both are real prices. Only one of them is a price you can act on this week.
💡 Price analysis PREMIUM VALUATION
📈 Price history
🏅 Graded value
🛡 Worth grading? WORTH GRADING
📊 Population PSA · CGC
🛒 Recent sales
Charts on this site show the last 90 days free; the full history is in the app.

