Not really, things like gas and munitions tend to be cheap. Before the war I made over 800k a day and me and a few others of my size could have easily bought all the gas and munitions on the market. Would that be economical? Probably not as alliances can just do internal trades and circumvent global entirely. Then, as the prices rose, more people would start producing and we would quickly start losing more money than we spend.
Simply put, it isn't hard to buy up the market at once. However, it is almost impossible to maintain control of it for any real amount of time.
I, and some of my friends, have done something similar before in Alpha with both food and steel. It was funny until sheepy released an update the next day to "fix" the trade system. (IIRC he either removed the trade limit for a few days or changed the min-max posting prices by 3 times)