"The option expiry date is not relevant either, as the option can be converted at any time prior to the expiry date."
Not quite right, these are European style options and can't be converted at any time, they can only be converted on the expiry date. That is one reason why they trade at such a discount.
Note: I couldn't find the announcement referred to above by GordonAcko. I searched CommSec, the ASX and the KDR websites and still couldn't find it. All I could find was this reference here on the KDR website:
"CAPITAL STRUCTURE
Kidman Resources Capital structure as at 31st March 2017
Total Fully Paid Ordinary Shares on Issue 333,331,373
KDRO Listed Options on issue 47,453,487
This is broken down into:
315,902,218 Fully Paid Ordinary Shares
11,111,111 Fully Paid Ordinary Shares – Escrowed to 28 Feb 2018
6,318,044 Fully Paid Ordinary Shares – Escrowed to 20 September 2017
Options are exercisable at any time between 9am and 5pm (AEST) on the Option Expiry Date being 30th April 2018.
Shareholders should note the the Options are only exercisable on the Option Expiry Date and may not be exercised at any other time."
http://kidmanresources.com.au/investors/capital-structure/