when will HKD Currency rise back?

Question

Its been constantly falling lately, hope it will rise back up at some point

Answer 1

Not sure where you are, but the Chinese government keeps the HKD exchange rate fixed vice the US dollar. As a result, as the dollar falls against, for example, the Euro, the HKD falls with it.
The HKD will only rise for one of two reasons: either the US dollar rising or the Chinese severing the link to US dollar.

The following link is to a web site that you can use to chart historical exchange rates. HKD hasn't budged with respect to the dollar in at least four years.