Which Characters in The Great Gatsby fit the description of stock, dynamic, and round?

Concerning the types of characters in The Great
Gatsby, I think that maybe no editors have answered your question yet,
because two of the three terms you ask about don't really apply to the novel.  I didn't
answer it the first time I saw it, either--I was hoping someone else might have a
complete answer for you, because I only have a partial
one.

In other words, I'm not sure any stock or dynamic
characters are really featured in the novel.  Characters are well-developed (the "round"
part of your question), but no often-used, stereotypical stock characters really exist,
and I don't know that anyone really changes much (dynamic).  Wilson is the possible
exception, with his murder of Gatsby and suicide, but he certainly isn't a major
character.

Even Gatsby, the most well-developed and
definitely round character, doesn't change.  That's what makes him Gatsby.  His love is
an idealistic, all-encompassing love, and he never gives up on his chance to get Daisy
back and recapture his past.  He's still waiting for a call from Daisy on the last
morning of his life.  He never comes to a realization or epiphany of any
kind. 

Gatsby is round, though.  He is a mystery man who is
shy, he's almost always polite yet seemingly uncaring about anything that doesn't
concern his quest to get Daisy back, has a library full of books but doesn't read them,
loves, perhaps, like everyone wishes he/she could love, was born fairly poor but becomes
extremely wealthy, makes his money illegally, at least in part, and yet is an obsessive
idealist. 

Daisy, too, is a round character.  She's a
victim of her patriarchal society, cynical, difficult to "read" or interpret,
manipulative, beautiful and knows how to use her beauty to get what she wants, and is at
least somewhat amoral.  Yet, though she despises Tom and may actually love Gatsby, she
refuses to say something that isn't true--that she never loved Tom, even when they were
newly married.  She rejects Gatsby, in the end, because she won't say what isn't true,
because Gatsby asks too much:  he insists that his dream is true, that Daisy's been
pining for him these five years, and never really loved Tom.  And Daisy won't say
it. 

Gatsby and Daisy are certainly round characters, but,
again, I just don't think the other two types of characters you ask about apply to this
novel.