A sudden spike like that does not create a base usually, it can be the result of sudden news or rumor that runs the price up, but the price where the news came out does not hold much significance for the big investors. Its just where the news broke...

When the price is falling and then stops and reverses with a huge spike, thats tells us that buyers are sitting at that low and would not allow the coin to go any lower. Thats a price that is significant.

But if a coin just suddenly takes off, without hitting a support level, then we are left wondering what changed? why did it just take off all of a sudden? You see, we don't know the story, and we don't know for sure if the take off price is significant. Trading shouldnt be a guessing game, you need the odds always skewed huge in your favor. I only take trades where I understand my odds.