"Speculative transaction" means a transaction in which a contract for the purchase or sale of any commodity, including stocks and shares, is periodically or ultimately settled otherwise than by the actual delivery or transfer of the commodity or scrips.
Example would be you purchase 100 Reliance Industries Shares at Rs. 1015/- and sell the 100 shares on the same day at Rs. 1020/- thereby earning a profit of Rs. 500/-. This profit is speculation profit.