Trading is related to Money. Money is related to Free. Free is a synonym of Spare. Spare is related to Part. 
Available is derived from Ability. Ability is related to Mind. Mind is a synonym of Attention. 
Trading <--RelatedTo--> Money <--RelatedTo--> Free <--Synonym--> Spare <--RelatedTo--> Part 
Available --DerivedFrom--> Ability <--RelatedTo--> Mind <--Synonym--> Attention 