Pokemon Market Index Methodology

The indexes

An index is one number that follows a basket of cards or products. Each index starts at a level of 1,000 on its start date, so a level of 1,050 means the basket's total value is 5% above where it started, and 950 means 5% below. Levels are index points, not dollars.

Every index is equal-dollar weighted, which means each member counts for the same dollar amount when the index is reset. It is reset every Monday, in what this page calls a rebalance: a weekly check of which cards belong, followed by a fresh equal split across them. The divisor is a behind-the-scenes number that keeps the level steady when members join or leave, so the level only moves when prices move.

Prices

Raw indexes use the TCGPlayer daily market price for each card's exact printing (its product and variant). When the feed records more than one value for a printing on a day, the day's price is their average. A card without a known printing is left out of every index.

The PSA 10 index uses recent trusted PSA 10 sales. Each card's price is a weighted comp of up to its 5 most recent trusted sales within 365 days. A comp is a price built from comparable sales: outliers are trimmed around a recency-weighted median, and each remaining sale is weighted by how recent it is, with a weight that halves about every 15 days. When fewer than 2 sales exist, a daily PSA 10 price estimate stands in. Each stored PSA 10 price is the comp as of the day it was computed; sales recorded later never revise published history.

How members are selected

DH Chase 100: English cards from the Sword & Shield era onward that are not sealed products, priced at $50 or more, and not flat across their 3 most recent weekday prices. Two rules feed the pool: the 10 most expensive cards in every set, and every Special Illustration Rare from Scarlet & Violet and Mega Evolution plus every Mega Ultra Rare from Mega Evolution. The 100 most expensive cards in that pool are the members.

DH Modern Sealed 100: English sealed products from the Sword & Shield, Scarlet & Violet, and Mega Evolution eras, priced at $100 or more. The 100 most expensive are the members.

Both indexes leave out the Prerelease & Staff Promos and Prize Pack Series sets, and every printing whose name carries a bracketed event, staff, store, or prerelease tag (for example [Staff], [Prerelease], [Professor Program], [Pokemon Center], or [Stamped]). A card is eligible on a date only once it exists: its set's release date, or the card's own release date when the set has none. Selection uses each card's latest price on or before the rebalance date, within 7 days. Cards whose price has not changed in 60 days are left out of every weekly selection (see the 60-day rule below).

Level, units, and divisor

The level is the sum of each member's price times its units, divided by the divisor. Units are how much of each member the index holds. On the start date each of N members gets units equal to (1,000 / N) divided by its price, and the divisor is 1, so the level is exactly 1,000.

The divisor is a scaling number. It is solved so that the level is the same just before and just after any change in membership. That is why a card joining or leaving never makes the level jump: only price moves do.

Weekly rebalance

At every Monday rebalance, the selection rules run again as of that day. The index value just before rebalancing is split into N equal dollar amounts, each member's units are reset to its share divided by its price, and the divisor is solved so the level is identical immediately before and after. Weights then drift with prices until the next rebalance. There is no rank buffer, so some weekly churn around rank 100 is expected; every entrant and exit is listed in each index's rebalance log.

If a Monday is a held day (see below), its rebalance moves to the next published day.

The 60-day rule

A member whose price has not changed for 60 calendar days is replaced. Prices that repeat because the feed has not updated count the same as prices that repeat because they were carried forward, and calendar days keep counting while an index is held.

On a Monday that publishes with a rebalance, the stale member simply leaves through the rebalance, and the rebalance log marks the exit as "no price change in 60 days". On a held Monday, or a Monday that publishes without a rebalance, the stale member is swapped out on its own: the highest-ranked eligible card that is not already a member and has a fresh price that day takes its place, with the same dollar amount as every other member, and the divisor is solved so the level does not move. If no eligible replacement exists, the member exits and the divisor is solved again. Swaps are recorded and listed with the rebalances.

A card whose own price has not changed for 60 days is never used as a replacement. If a stale member has no replacement and removing it would leave an index below its minimum size (1 member for the DH Chase 100 and DH Modern Sealed 100, 10 for the PSA 10 and sector indexes), it stays, and the case is logged. Each index applies the rule to its own prices. Sector indexes follow their parent's swaps, and a replacement joins a sector only if it matches the sector's filter. The PSA 10 index follows the DH Chase 100's swaps and also swaps out members whose own PSA 10 price has not changed for 60 days. Because calendar days count while an index is held, this rule also lets an index recover when a block of stale members has held it back.

Fresh, carried, and dropped prices

A raw price is fresh when the feed has a value for that day. A PSA 10 price is fresh when it comes from the weighted comp or the daily estimate and the card's most recent trusted sale is no more than 30 days old. A member without a fresh price carries its last price. After 7 published days carried, it is dropped: it leaves the index, the divisor is solved so the level does not change, and its weight is not redistributed until the next rebalance. A dropped card can return only at a rebalance.

Three things follow from these rules. First, a card can join at a rebalance with a last-known price that is already several days old and then carry it, so a stale entrant's price can count for up to about 13 days in total before the card is dropped. Second, the drop happens on the 7th published day carried; held days do not count toward it. Third, each drop makes the divisor smaller, and drops are not reversed between rebalances. That is ordinary index arithmetic and does not change the level on the day of the drop.

Published and held days

A day publishes when at least 90% of index weight, at the previous day's prices, has a fresh price. Otherwise the day is held: the level repeats the last published level and nothing else changes, so a feed outage never ages members toward a drop. Every day from the start date onward is either published or held, and the daily CSV marks which.

The PSA 10 index

The DH Chase 100 PSA 10 has its own units and divisor. At each DH Chase 100 rebalance it takes the same members, minus any without a fresh PSA 10 price that day, and sets equal-dollar units at PSA 10 prices. Between rebalances it applies the carry and drop rules on its own, so a raw drop does not drop the PSA 10 member, and the reverse. Its start date is the first Monday on or after March 1, 2026 that publishes with at least 10 members. The median PSA 10 price multiple is the median of each shared member's PSA 10 price divided by its raw price.

Sector indexes

Sector indexes take the members of their parent that match their filter (an era, or a sealed product type) at each parent rebalance, with their own units and divisor. A sector starts at the first parent rebalance where it has at least 10 members and the day publishes. If a later rebalance leaves fewer than 10, the sector is held until a rebalance restores 10; it is never silently removed.

Reconstructed history

Days before the methodology launched in October 2026 were rebuilt day by day with the same rules and the prices available for each day. They are marked as reconstructed. Rarity, era, set, and sealed type use today's catalog values for every date, so a card reclassified since then is treated as if it always had its current label.

Risk and breadth statistics

Return-based statistics use returns between consecutive published days; held days are skipped, not counted as zero returns. Volatility describes how much the level swung from day to day: it is the standard deviation of daily log returns over the last 30 days, scaled to a year by multiplying by the square root of 365, and a higher number means bigger swings. The largest decline from a peak (the maximum drawdown) is the biggest drop from a high point to a later low, measured since the start. The 52-week high and low cover the last 52 weeks, or the time since the start for a younger index. The correlation between chase cards and sealed products, a measure of how closely the two moved together, uses the last 90 days both indexes published and is shown with at least 60 such days.

Breadth counts members that rose, fell, or held within 0.05% over 1 and 7 days, and the share priced above their 30-day average.

Written summaries

The short daily and monthly summaries on the market pages are generated from the index data. They describe direction in words and contain no numbers. Every number on every page comes from a fixed template that reads directly from the index data, and the numbers appear next to the summary.

Data license

Index-level data (daily levels, changes, risk statistics, and the history CSVs) is licensed under CC BY 4.0. Per-card prices, card images, and catalog data are not licensed. When you use the licensed data, credit it as: Source: Double Holo Research, doubleholo.com/pokemon-market.

Reports, data, and citation

A frozen report is generated on the second day of each month for the month before and never changes afterwards (see the report archive). Each index has a free daily CSV that opens with a comment line stating the license and credit, for example the DH Chase 100 history. Please cite as: Double Holo Research, index name, date, and page URL.

Versions and changelog

A methodology change bumps the version and adds a dated entry here. Published history is never rewritten, and frozen reports keep their numbers.

Index levels describe past prices only. See the market overview for today's numbers.

Index levels and statistics are informational only and not financial advice. Past performance does not guarantee future results.