Members will be able to see your profile (which includes your full name, a profile picture which you can upload, and a custom bio), your holdings, trading activity, watchlist, and comments.
While others can see the products you hold or trade, they will not be able to see the underlying quantity or values of such transactions. For example, they may see you bought or hold Amazon but not the value or quantity of your holdings and transactions, whether it be 1 or 100 shares!