Invest in gambling?

Neither of them laughed.
“It’s too early?” I joked. “But I mean. I think we should talk about the difference. Even without sports betting or something like that, I will do that.”
“Yes, yes,” Oliver murmured.
Is investing like gambling?
“Oliver,” I said seriously, “I’m not going to be cheap shots. Indeed, some people think that investing is gambling. It’s not at all, and it’s important to understand the difference.”
“Okay, very good,” he said meanly.
I’ll continue. “Sometimes, when we talk about investment, we talk about this thing called a risk-reward tradeoff. It’s an investment principle, and basically, the more risk you take, the more potential returns you can get. The return is the money you make, or you can make money.”
“Like a slot machine,” Oliver said. “If you play a slot machine for a cent you won’t lose too much money, but you won’t make a lot of money either. If you play a slot machine for a $5 you may lose more, but you will add more.”
Given this situation, I was a little scared of gambling reference, but he had a little bit. “That’s a good point. But again, I’m careful not to compare gambling with investment.”