Understanding Put Warrants on SET (Thai) exchange

Question

I have having trouble understanding exactly how these derivative products work.

For example this one.

I understand that the European exercise style means that they can only be exercised on the stated date of February 4, 2019.

Assuming I were to buy some of these, I assume they can be traded but not exercised before that date. There is a Last Trading Day, an "Automatic Exercise Date" given as well as an Expiration Date (the next day).

So if I buy some of this product, and assuming the underlying stock has dropped below the exercise price of 434 THB, what exactly happens between January 30 and February 5 expiration? Are they automatically sold or what?

Bonus question (Canada) is the cost of buying the warrants deductible and how is any profit taxed?

Answer 1

My best guess is that the warrants continue to have their appropriate value as contracts until expiration, but the exchange simply doesn't allow them to be traded on the intervening days (much as securities retain value when they aren't traded on weekends). If you hold one and don't want to keep it until expiration, you need to sell it by January 30.

Perhaps there is a technicality where the exercise right corresponds to the warrant's holder of record, and so they allow time for settlement of all trades before the exercise date?

Incidentally, because the warrants are listed as cash-settled, there must be a rule for how an expiration price for the underlying is determined -- presumably an opening, closing, or average price on February 4.