Card Trader is a Continuous Spell Card.
Spell Cards are usually activated from the hand on your turn unless their type gives another timing window.
On the current TCG and OCG Forbidden & Limited lists tracked here, Card Trader is Unlimited.
YGOPRODeck lists Card Trader for these formats: Duel Links, Common Charity, Edison, TCG, OCG, Master Duel.
A listed print of Card Trader appears in Battle Pack 2: War of the Giants (BP02-EN150) at Mosaic Rare rarity.
Among markets shown on this page, the lowest listed snapshot for Card Trader is about $0.09 on Cardmarket (prices change frequently).
