Of course they gamble on the stock and currency markets. The WTBTS has controlling stock in Randcam - it supplies military contracts to the US (missile engines and drones) stocks in Philip Morris the tobacconist, Kraft foods, gilts, and still own more real estate via dummy companies (one called "National Cemetaries" or something like) than the Catholic Church in NY.
They spend literally hundreds of thousands a year buying in advice from worldly financial companies. The WT reps who deal with them have business accounts, to pay for corporate entertaining.
I know - a friend was "cultivated" when he visited Crooklyn ( he owned his own comany). He was shown around upstairs - one of the drones remarked: "You must have money if they brought you up here".
And, yes he met one of the worldly financial advisers, and the brother paid for the whole evening on his business expense account.
One of the brothers there that evening was thrown out of Beth Hell a few weeks later, along with the sister he had been poinking.