Guiness World Record?
 

Larry Fritsch had many, many millions more cards than that. When I was a full time dealer in the mid 1980s my initial orders from Topps were 300 vending cases (3.6 million.) The guy I sold my commons to, Larry Grossman (Hygrade), must've had well over 10 million cards in his Vermont storage units.

I'm positive there are many collectors/dealers who have, or have had, more cards than this guy at some point.

That is a big amount in the original post but I also don't think it would be the largest ever, though that is just a hunch from what I have seen.

Not that I necessarily disagree, but I don't think "inventory" counts it has to be a PC. If inventory counts it's not even remotely close. As a personal collection it's pretty huge.

The local shop sold their commons to a liquidator when they moved.

1.5 million cards..... And it wasn't exactly a huge place.

I guess the number depends on documentation also...looks like he has every card recorded... Guinness requires such things to verify. Ofcourse many dealer/collectors like Larry F had much more...but I wonder what the breakdown was in terms of collection vs inventory.

Ricky Y

2.5 million is more of a hoard than a collection.

That's not a collection, but just a massive accumulation...imagine the size of building it would all require if each card was slabbed!

Brian