S. 73 : Losses in speculation business-Futures and options derivative transactions-Deriving 69 Per Cent. of its gross total income from various heads-Explanation is not applicable-Business loss and can be set off against other business income-Derivatives carried out in recognised Stock Exchange through registered stock broker-Transaction not deemed to be speculative transaction-Eligible to be set off-Apportionment of expenditure is directed to be followed. [S. 28(i), 43(5)(d)]