putting their money in the market rather than losing their advantage by broadcasting the prediction to the rest of the world I think you're missing the point.

putting their money in the market rather than losing their advantage by broadcasting the prediction to the rest of the world I think you're missing the point. You first put your money in the market and then broadcast your prediction to make the market move in the direction you want it to move. They're not trying to predict the market, they're trying to influence it.