Where an instrument is chargeable with ad valorem duty in respect of any stock or of any marketable or other security, such duty shall be calculated on 2[the market value of such stock or security.]
3[Provided that the market value for calculating the stamp-duty shall be, in the case of—
(i)options in any securities, the premium paid by the buyer;
(ii)repo on corporate bonds, interest paid by the borrower; and
(iii)swap, only the first leg of the cash flow.]