Dan,
Depending on who you are dealing with. Sometimes a trade is only wanted or sometimes only to sell is wanted. Even sometimes part trade--part buy is ok. Generally what is agreed on by both parties involved is OK.

Usually trading is what goes on. But buying is OK also. There is NO rule as far as I know. That says ONLY trading at this trade session in January
Dan

Note:

Dan, at all the trade sessions at the CC&TCC Convention. ONLY trading is allowed at all the trade sessions. NO BUYING. (CC>CC convention attendence rule)This goes for the halls outside of the convention also.(Also CC>CC rule)Buying ONLY in the convention dealers room. So if you do want to do some buying outside of the dealers room at the convention. I suggest you do it somehow away from the Riviera Convention Center.