If the quantity of chips can actually move the market, like the sale of a lot of one stock, then the concept of disclosure should be an issue. If the quantity realistically will, in all probability, not move the market, (AND THE SELLER PROBABLY KNOWS WHICH IS WHICH), then I don't believe you have a responsability to disclose the total of your ownership, it would invite people to press you to lower your price when there is, in essence, no justifcation to do so.