Bitcoin is 40,9% off the all-time high that it reached 4 months ago on the 10th of November. If we look at the below chart I have compiled, it would require a greater than 66,67% gain to reach that high

So what standard deviation can tell about an interval of data? Simple. It tells you how sparse the values of your variable are from the mean. For example lets take an interval X = {1,2,3,4,5,6,7} it yields