1952T Mantle price drops

[brunswickreeves]

Originally Posted by Snowman

I think of a commodity card as being any card that is effectively as good as cash. A card with both sufficient supply and demand. One that trades often enough that it is easy to comp and easy to predict the hammer price of the next sale.

To your other point about waves of similar cards hitting the market at the same time, this is something that the market doesn't seem to understand very well. Sure, keen observers recognize that it has some effect, but I think it brings about inefficiencies in the market that aren't well understood in general. For example, if you want to know whether a card has "hit the bottom" or not, you can get a pretty good idea by looking at the time series of the number of days between sales and plot it in a chart, then take the derivative of the slope of that curve and you can get a pretty good idea of when a card is in a bubble that is about to pop or if it's at it's floor by comparing that time series against what other cards' time series with similar pop counts look like, or by comparing it to what it otherwise looks like during "normal" times.

How is this derived when there isn’t a large enough sample size to warrant statistical significance? M101-2 Sporting News Supplements come to mind.