This week Sig goes back 24 years to examine the value of Portal and Portal: Second Age cards. Their age, rarity, and unique nature mean they could offer some real upside…or some significant risk, depending on how you look at it.

Domestic arbitrage gets less press, but opportunities are available if you know where to look—the more obscure the card, the better. Sig looks at some that may be overlooked.

David Schumann continues his review of eternal staples, this time focusing on rare and little-known gems from the Portal series.