Can a stock market trader claim car depreciation ?

Hi , Please help me , I have query :

a) Can stock Market Trader of F&O claim Car Depreciation ? (If i buy car and claim it).

b) I also trade in Crypto Currencies , so can i show that as business income ? ( I am already showing business income from Stocks for past years in ITR).

c) Do i need to maintain book of accounts if take a CAR ? or not required?

d) Can i buy a Car , without opening a Firm (soely on Invidual Trader Name) 

FYI...I also have Salaried income .

Kindly help.

Regrads

Harsh