How we benchmark TCG eras against the S&P 500

Every era page on Cardboard Assets shows the same comparison: a basket containing every booster box released during the era, dollar-cost-averaged at MSRP as each product released, vs the same dollars dollar-cost-averaged into the S&P 500 Total Return (^SP500TR on Yahoo Finance).

This is the DCA method, not the lump-sum method. The reason is simple: it’s the comparison an actual collector — buying a box on release day, holding to today — would experience. Lump-sum at era inception would be apples-to-oranges.

We use SPXTR (total return, dividend reinvestment) rather than the price-only S&P 500. Including dividends is the honest baseline; price-only would systematically understate the equity benchmark.

The basket-value series and the SPXTR-DCA series share monthly time grids. Where we have actual sealed price history (sealed_prices_history, courtesy of PriceCharting median sold comps), the basket walks with the market. For periods before the history begins, we hold MSRP — a known data quality issue we surface via the SealedHistoryDisclosure footer on every chart.