The banian manufacturer’s personal stake (6,8)
I believe the answer is:
vested interest
'personal stake' is the definition.
(I've seen this before)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for vested interest that I've seen before include "It could be good for you!" , "Having personal concern" , "Personal stake in an undertaking" .)