You are the owner of the marketplace, therefore it is up to you to decide when the marketplace is open or closed. If the marketplace is open vestors can trade eyecons with each other. You can also decide who can see your marketplace (if open); only the current vestors or all the Eyevestor users.
You can decide the marketprice of the eyecons of your business, with a certain spread %. Within this price range should the price of eyecons offered in the buy and sell orders be. The marketprice is usually the same price as you would ask for an eyecon during a(n) (new) ECO.
Example: Marketprice is set on €24 with the spread % of 20%. The minimal price is €19,20 and the maximum price is €28,80.