Economic is related to Market. you are likely to find Fish in/at/on Market. 
Sequence is a type of Series. Chain is a type of Series. Chain is a type of Unit. Unit is related to Bullet. 
Economic <--RelatedTo--> Market <--AtLocation-- Fish 
Sequence --IsA--> Series <--IsA-- Chain --IsA--> Unit <--RelatedTo--> Bullet 