Defective return u\s 139(9)

Hi,

Could u please assist me on below?

For AY 2014-15,I filled ITR-IV  and booked the following

A) STCG from Trading in Shares 

B)  Loss from trading in F&O  ,I showed that loss in NO Account case  in Number 53) Business Income 

I Got set off of this loss from STCG.But now I Got Notice From AO stating that I cannot book a negative number under pt 53) 

Note: I do not maintain books of Accounts ,since this trading is just for investment purpose.How shall I book this loss now to get the set off?