Thanks for the reply

I have question for you, if I send SBI to @null, what happens there? Is that a case where their balance will just increase forever? But if that's the case why isn't there balance higher? I just looked and they have around 300 units.

It's all behind the scenes complicated (though it's actually a few simple rules that I follow that result in behavior that looks a lot more complicated than it actually is).

Its really interesting how easy it is to create complex systems with only a few changing variables. I really don't think a lot of people appreciate that.