HoodCar Index · HCI

Methodology

The HoodCar Index (HCI) is a family of daily benchmarks for the graded trading-card market. Each index measures how aggregate floor prices move within a defined category or label — not investment advice, not a security, and not affiliated with S&P Dow Jones Indices LLC.

18+Category indices

DailyIndex snapshot (~00:00 ET)

6 hrLive floor refresh

eBayPSA · BGS · SGC · CGC

1. What HCI Measures

Term	Definition
Floor	Lowest current asking price among qualifying live graded listings
Floor Value	Sum of current asking prices (inventory exposure, not market cap)
Median	50th percentile of current asking prices
Index Level	Normalized score anchored to a base date; compare within one index only
% Change	`(today − prior) / prior × 100` over the stated window

Important: An HCI level of 1,200 in WNBA is not comparable to 850 in Baseball. Compare only a single index to its own history — the same rule as Dow vs. Nasdaq.

2. Index Families

Category Indices (18)

Baseball, Football, Basketball, Soccer, Pokémon, WNBA, Golf, Racing, UFC, Marvel, Yu-Gi-Oh!, MTG, High-End, Vintage, and related categories.

Label Indices

Player, set, or theme labels (e.g., jeter, pikachu, charizard) scoped to matching listings from live floor search.

HoodCar Composite (HCI-ALL)

Optional flagship index: liquidity-weighted blend of top categories by listing count.

3. Inclusion Rules

eBay listing, graded (PSA, BGS, SGC, CGC)
Buy-It-Now or auction with at least one bid
Title matches HoodCar category classifier
Minimum ask: $25
Maximum single-listing weight: 5% of category floor value
Exclude asks greater than 3× category median
Exclude best-offer sales where final price is hidden
Exclude relisted duplicates (same cert number within 30 days)

4. Calculation

Modified Laspeyres-style price-relative index.

price_i(t) = current ask  (auction: current bid if ≥1 bid)
S(t)       = Σ price_i(t)
HCI(t)     = 100 × S(t) / S(t_base)
Δ%         = (HCI(t) − HCI(t−W)) / HCI(t−W) × 100

Rebalancing: Quarterly. Divisor adjustment when constituents change (Dow-style technique).

5. Sold Comps Layer

Separate from the floor index:

Completed eBay graded sales, rolling 30 days
Median, average, and count by card name + grade
Up to 7-day verification lag

6. Data Refresh

Layer	Cadence
Live floor listings	Every 6 hours (eBay Browse API)
Daily index snapshot	Once daily, ~00:00 ET
Movers endpoint	Day-over-day: latest average vs. the prior daily snapshot
Homepage category chips	Day-over-day change vs. the prior snapshot

7. Limitations

Reflects eBay graded inventory only — not private sales or other marketplaces
Auction prices before close are provisional
Thin categories (fewer than 50 listings) flagged as low confidence
Past performance does not predict future results

8. Transparency Downloads

Planned public artifacts (post-launch):

Daily index CSV
Constituent counts per day
Divisor change log
API changelog

9. Legal Notice

HoodCar Index (HCI) is published by Hoodcar Corp for informational purposes only. HoodCar is not a registered investment adviser, broker-dealer, or commodity trading adviser. HCI is not sponsored, endorsed, or licensed by S&P Dow Jones Indices LLC or any other index provider. “S&P 500” is a registered trademark of S&P Dow Jones Indices LLC; HoodCar uses it only as a general analogy, not as a product name.

Methodology corrections: info@hoodcar.com

10. Changelog

Date	Change
2026-06-16	Initial methodology published