Downside protection

Hi all,  been holding for a few years now and sitting on nice unrealised gains.  I subscribe to the theory that a decision to hold is the same as a decision to buy, and right now I am not sure I would buy my current holding at today's price with the downside risk associated with the trial results.

I am considering taking out some downside insurance by selling half my holding and buying an equal number of mini warrants:

https://au.citifirst.com/EN/Products/MINIs/SIRTEX_MEDICAL_LIMITED/SRXKOC/

I have never used derivatives before, but I've never had a large unrealised gain worth insuring before.  Any thoughts on using the above for insurance at the moment?  I understand that they limit the downside to about $26 being the current stop-loss level.  BTW, I also cannot find the interest rate applicable to these at the moment?

To be honest, I am not sure I will do this but am interested in what others think, and also might prompt some people to consider if these are right for them at the moment.

Cheers,
oakeyflat