<h1>Speculation business exclusion: principal-share-trading companies exempted from deemed speculative status, altering set-off rules going forward.</h1> The amendment excludes companies whose principal business is trading in shares from being treated as engaged in speculation business under the Explanation that limits set-off and carry forward of speculation losses, thereby exempting such companies from the rule that speculation losses may only be set off against profits of other speculation business and applying prospectively from the stated operative date to subsequent assessment years.