"what happens if TIM falls below 50c? How do you lose out if its lower than 40c ??"
If TIM falls to $0.40, you will still get 4 shares, which worth $1.60 and plus dividends, better than today's close of $1.35.
But the real problem is what if "30c is a real possibility", just as Alpha said months ago.
http://www.hotcopper.com.au/post_single.asp?fid=1&tid=616204&msgno=2529526#2529526