Your problem is that you seem to think that 100% represents the same starting point in both examples. It doesn't. In the first example 100% represents 1c. In the second example 100% represents 11c.
Let's suppose I buy a share at $10, On the first day it increases in value by 99%. It is now worth $19.90. On the second day it decreases in value by 99%. It is now worth 19.9c.
What the f***? There is no trick here. We have simply taken two different values as our 100% starting point.
