" If the EVG sp is below, say, 19.4 in Dec this year then you've...

" If the EVG sp is below, say, 19.4 in Dec this year then you've done your dough (assuming you bought today)? "

You haven't quite done your dough under 19.4, but you'll be running at a loss. You can choose to convert, which means they'll have cost you 19.4 (15 + 4.4), but if they're trading at 16c then you're down ~20%. However, if they're trading below the exercise price (15c) then it wouldn't make sense to convert in which case you've gained a capital loss.