As the largest rookie card dealer on eBay who always seems to have the hottest players, we often get asked when is the right time to buy a player and whom to buy.

Here's the copy of a letter we sent an investor collector in January of 2008.
-----------------------------------------------------------------------------------------------------------------------------------

January 13, 2008

You need to start looking at cards like stocks. There's short term growth, long term growth, turn and burn, etc.
 
It depends on what your model is.
 
For me it's putting away the Hall of Famers and likely Hall of Famers. I also grab rookies that look really strong like Adrian Peterson before they go ballistic. But I won't overpay into a frenzy and I do kiss my share of frogs. You can raise your success level by considering whom the player is going to be playing for. If you know he's going to ride the pine for a season, it's better to pick him up later when the herd of buyers have lost their enthusiasm.
 
With existing players, what you've got to do is look for value and upside. Derek Anderson is an example.
 
Or, have Greg Oden's rookies fallen enough to make him attractive? His Portland team is much better than anyone thought and when he comes back next year he comes back to a likely playoff team.
 
Don't follow the crowd, get in front of it.
 
There's an axiom in traditional investing, "Buy on Rumor, Sell on News."

The way to convert this to the hobby is to suggest that sometimes a player will never be hotter than in BEFORE his rookie year, when wild expectations fuel card price appreciation. Think Reggie Bush.
 
Bush had a strong season but when it wasn't world-changing, his card values fell.
 
You want to look for an underappreciated opportunity. That's where there's growth and profit potential.