Do someone here know about bitcoin halving?
Is there a problem when bitcoin halving hits?
Is it better to buy bitcoin when bitcoin halving come?
I think by now you already know what bitcoin halving is and I don't think there was a problem when it occurred last 2016. It is also a speculation it'll happen in 2020 because the first one occurred on 2012 then the next happened in 2016, so rumors has it it'll happen 4 years after because of the year difference. And if eve that'll happen by then, it might be a good time to buy bitcoins too.
Uhh, that's not a rumor if you know what halving really is. Halving is not something that just occur out of the blue. It is a feature of bitcoins and it is hard coded in it's scripts that is why it happens. If you think it was just coincidence that it happens that way then you're quite wrong and you should read up on what bitcoins really are.