“Open Air " is likely the name of a radio programme, perhaps on the BBC; it is neither likely for it to be a kind of commodity nor for anyone to to trade stock in it; even less possible for any radio programme to be anyone's stock trading monopoly, virtual or not. Apart from that, what do you make of this: "Walter compèred the Open Air in the shape of a poacher, etc.". Did he change his shape? A shape-shifter on radio? And this "For the latter half of his time Walter merely talked." What else can you do on a radio programme but talk? Was he singing at some point in time? What is "merely talked"? When I see a puzzling passage like this one, I know it's time to throw the book away and start reading one by a better author. Please don't miss out on the old classics: H. Rider Haggard, Edgar Rice Burroughs, G.K. Chesterton, Conan Doyle, Bertrand Russell (the best English phrasing I have ever read), Somerset Maugham and so many others.