Ann: Becoming a substantial holder in SDL by DB G, page-4

re: Ann: Becoming a substantial holder in SDL... Correct me if I'm wrong but if I bought and sold like that I'd be answering to someone. Or is that only if I was reducing my tax?
If they has to explain their fundamental investment strategy insofar as SDL goes what would it be if not to say we buy and sell and generally manipulate the share price?