you think this is the right time to buy and hold bitcoins? because from 19k its 11k today.

It would seem. Buyers are supposed to buy at the lowest price they could, to generate a bigger profit. If you buy bitcoin now at 11k, then it pump up again at 19k or more, that is a lot of profit. We should really take advantage in every opportunity that this technology is offering us, since bitcoin's price is so volatile, we should be aware of the price trend. Stay focus and grab every opportunity to earn.