Mate it would help if you could be more specific with references...

Mate it would help if you could be more specific with references to “these” shares etc. Assume you mean in speccie DRM but that’s were people could struggle to answer with assumptions.

I will have a crack at it based on the process I have used.

Take your total holding of ADN shares post buy out and the total $ amount you paid for them (obviously in your case whatever you paid for the MEP prior to T/O as you sold all ADN)

Divide $ amount by number of shares. This is your average for your new ADN holding (without reducing for value of DRM)

Next step is to work out the value of your DRM shares based on the IPO price or value that we have been told is assigned to them. You then need to deduct this from your ADN average above to get a new base for ADN. For GCT on ADN you need to hold for 12 months from the date you acquired the original MEP (assuming you got rollover relief). This was one of the downsides of selling potential long held ADN to buy MEP for arbitrage the reset of the 12 mths, however looks irrelevant since ADN have tanked.

For your new DRM your cost base is the price per share or value assigned to them in step 2 above.

Hope this makes sense. Not financial or tax advice and you should confirm with an accountant.

Happy for others to chip in if I’m incorrect here.