Speculative financial venture involves seedy accommodation (6)
I believe the answer is:
billet
'accommodation' is the definition.
(I've seen this before)
'speculative financial venture involves seedy' is the wordplay.
I cannot quite understand how this works, but
'seedy' could be 'ill' (seedy can mean unwell) and 'ill' is present in the answer.
'venture' could be 'bet' (bet is a kind of venture) and 'bet' is located in the leftover letters.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for billet that I've seen before include "Housing for military personnel" , "Place for a soldier to stay" , "Lodging for troops in private house" , "letter in Paris" , "Military lodging - little note" .)