All investment is gambling. Investments have different risk profiles, sure. But unless you can perfectly predict the future then the uncertainty is non-zero and it is a gamble.

But when investing how much an investment makes absolutely isn't very interesting. All that matters is opportunity cost, or how one investment compares to all of the others. You want to make the best investment for the right amount of risk - and this is going to always be a gamble because it is highly uncertain.

So you want to talk about how much energy casinos around the world waste?