Data Report · July 16, 2026

PSA grading and One Piece sealed supply: what weekly population data shows

Research and data: OP Box Index · Published July 16, 2026 · Updated August 10, 2026 · Data sources & methodology

Between June 3 and July 8, 2026, collectors added 99,646 One Piece Card Game cards to PSA's population report across the 21 sets we track, an average of about 16,600 cards per week. Those additions measure grades posted during the period, not boxes opened during the period: submissions can come from recent pulls or cards held raw for months. This report shows the set-by-set data and explains what the signal can and cannot tell a sealed-box collector.

Why grading volume is an indirect sealed-market signal

Every graded card originated in an opened product at some point, so cumulative population records part of a set's historical opening activity. Weekly additions do not identify when those packs were opened, whether they came from booster boxes, or how much sealed stock remains. We therefore read grading volume as collector-submission activity and pair it with release timing, box listings and completed sales instead of treating it as a sealed-supply counter.

The six-week leaderboard

OP-13 Carrying on His Will dominates the period with 18,303 new grades — more than 18% of all One Piece grading activity — peaking at 3,712 cards in the week of June 17. Its manga-art chase cards, led by Monkey D. Luffy's manga rare, make almost every strong pull worth grading. OP-14 The Azure Sea's Seven follows at 13,749, and OP-12 Legacy of the Master at 7,839. At the other end, OP-16 The Time of Battle registered only 61 grades — it released at the end of May, and the first submissions are only now returning from PSA.

Weekly grades are week-over-week changes in PSA's published population report, collected each week (Jun 3 - Jul 8, 2026). All-time population and gem rate cover the set's tracked chase cards. Gem rate = PSA 10s as a share of all grades for those cards.

Reading the numbers: three observations

1. Older sets still attract submissions

OP-01 Romance Dawn is three and a half years old, its Japanese box had risen to about $313, and 3,504 of its cards were added to PSA's report in six weeks. That shows older-set cards were still worth submitting despite higher sealed prices. It does not prove those cards were pulled during this six-week window; some may have been held raw before submission. OP-05 recorded 4,866 additions while its English box traded above $1,100.

2. The grading wave follows the release wave, with a lag

OP-13 released in Japan in late August 2025 and remained the most-submitted set in this window, while brand-new OP-16 barely registered. Population reports lag the underlying activity because cards must be selected, shipped, graded and posted. A rising series confirms more grades are entering the population, but it cannot separate recent pulls from older raw inventory.

3. Gem rates cluster near 87% — and that shapes premiums

Across the 21 sets, gem rates for tracked chase cards run from 83.5% (OP-03) to 90.8% (OP-15), clustering around 87%. These rates describe submitted cards, not every printed copy: collectors screen condition before paying a grading fee, and the card mix differs by set. A lower rate means fewer PSA 10s among the tracked submissions, but it does not identify the cause by itself. Our PSA population and prices guide explains how to use the figure with completed sales.

How to use this on the site

Every set page on OP Box Index shows the set's population, its top-10 chase cards' PSA 10 counts and gem rate, and Japanese/English totals with the change since the previous week. Pair that panel with the box-price chart and completed sales. A rising population alongside a rising box price is a useful comparison, but the data alone cannot say how many boxes were opened or why the price moved. Start with OP-13, which led this recorded grading window.

Methodology and limits

We snapshot PSA's public population report weekly and record the change as that week's new grades. Numbers cover Japanese-language One Piece cards in the sets listed; PSA does not break out language in every case, so mixed-language populations are possible on some entries. Weekly deltas can be slightly lumpy when PSA posts grades in batches. All-time populations count the tracked chase cards per set rather than every card in the set, so they understate total set-wide grading. We publish the series as collected and correct it if PSA restates figures.

FAQ

Does heavy grading make my sealed box more valuable?

No. A new grade increases recorded slab supply, but the population report does not say when its source pack was opened. OP-15 added 3,307 grades during this period while its box price fell 13%. Grading volume is one input, not a verdict.

Why does a new set like OP-16 show almost no grades?

PSA turnaround. Cards from a late-May release only started posting to the population report in late June — its 61 grades will multiply over the coming months as submissions return.

Is a 96% gem rate on OP-16 real?

It is real but early: with only 82 total grades, the rate will move a lot as volume arrives. We flag small samples on set pages for exactly this reason.