Bit of capital — one thousand pounds I invested in power firm (7)
I believe the answer is:
pimlico
'power firm' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.
'bit of capital one thousand pounds i invested' is the wordplay.
'bit of capital one' becomes 'pico' (I can't justify this - if you can you should give a lot more credence to this answer).
'thousand' becomes 'm' (Roman numeral for a thousand).
'pounds' becomes 'l' (L can represent the monetary pound).
'invested' means one lot of letters goes inside another.
'm'+'l'+'i'='mli'
'pico' going around 'mli' is 'PIMLICO'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for pimlico that I've seen before include "District of London" , "aka South Belgravia" , "Passport to - (nineteen forty nine Ealing comedy)" , "London area near Victoria" , "Passport to - was an Ealing comedy film" .)