Value of shares in players' organisation (6)
I believe the answer is:
equity
This clue is a double definition.
'value of shares' is the first definition.
'players' organisation' is the second definition.
(UK union for theatrical industry)
'in' is the link.
(Other definitions for equity that I've seen before include "Fairness for actors' trade union" , "actors' group" , "Group of performers" , "Even-handedness" , "Fairness or impartiality" .)