I've been playing the game for about 2 weeks now (on Windows Phone 8.1). I have 30 main levels and 5 subs. Some of my shops range in rank from 3-5 and vary in the 1000-4500's for the 3rd character's stock.
The issue is, what determines the capacity of stock? I have looked into the charater's strength areas (dream jobs, all team members within same related job field/color). I also looked into when the shops where created(lower levels vs higher levels). etc etc.
I can't seem to find out what makes two shops with similar crew skills and rank be so drastically different in stock capacity.