It's not really a sign or anything. It just happened, and it happened as a result of a strong support at $6600, which people believed it to be the bottom. It's obviously nice to see some renewed optimists in the market.

Although I'm not sure if we should jumping straight to the conclusion that this must be the start of a bull market, yet. But institutional investors seem to be piling up during this pump, so I guess it's definitely a breath of fresh air from the bearish state that the market was in for months.

And furthermore, even though I'm optimistic of what bitcoin will do in the long run, I think this rally is nearing its end. Even if it does break 5 digits, the resistance at levels higher like $12k have proven to be stronger than most expect from previous attempts. In fact, when BTC last tested the $12k that was when the huge dump down to $6k occurred. I'd say the fact that BTC is at $9k+ only calls for careful optimism, not irrational buying.