Bitcoin is not so strong, we can say, it is just the beginning. Even marketcap is not much more that's why many country don't have any rule for it's regulation. It's price value is always volatile in nature. We cannot compare it with any country's currency since they are stable, but bitcoin may not be.
No, I think the Bitcoin price controlled by the whale, it can not pumped a lot of value to $6,000 without whale use their money to pump it first. Then, after the whale pumped the Bitcoin price, the traders heard some rumors about receive Bitcoin Gold and Bitcoin SegWit2x make many traders FOMO to buy Bitcoin.