Pinning soft body

Hi there,

I hope someone can help me figuring out the following:

I want to make sorts of bulbs (see image below) using Soft Body (not pinning with cloth, because I don’t want any folds/wrinkles):

Important here is that I can pin a vertex (or vertex group) at the top and simulate the rest of the object, using Soft Body.
(this example was made manually)

I tried using the Hook modifier, but couldn’t get it to work.
Please help me out.
Thanks a lot!