Yes I think it can be considered as a high risks investment these days because its something that is risky due to the fact you need luck and its also that you really have to invest money with high risks if you are playing.
First, think you should understand is that gambling is not at all an investment because it is just an entertainment activity and got a chance to win money if you're lucky. But most of the people like you understood wrongly and spending their money to win and end up losing a lot of money in gambling. Don't waste your money in gambling instead, invest some other places if you want to grow your money.