Demerger + stock spilt


Can you advise how do we implement these corp actions for this counter GSK?

Hi there,

Can you help me summarized what is happening? Tried reading it but seems quite a bit going on.


Let me try to explain, for this counter GSK in LSE, there are 2 events:

  1. De-merger. Every 1 GSK PLC share entitled to 1 HALEON PLC share.
  2. Reverse Stock Split: 4 for every 5 unit(s) of existing GSK PLC share.

I have 865 units of GSK, so i will have 865 units of new HALEON share. After which my 865 units of GSK will be reduced to 692 units due to reverse stocksplit.


To me, it means that every share of old GSK PLC became 0.2 shares of HALEON PLC and 0.8 shares of new GSK PLC.

When it is going to happen?

What I propose is this.

  1. Sell GSK PLC at the price of the close when it happens.

  2. Buy same shares of HALEON at 0.2 x price of GSK PLC at the close

  3. Buy 0.8 shares of GSK PLC at price of GSK PLC at the close

I can build this into the event if you agree with this and give me the day this is happening.

All events completed on 19 July.

Done. If you go to the events page, you should see it →

May i know how do you derive the cost price for HLN 356.68 and then the buy price for GSK 1783.4? My actual cost is GBX 1,371.25. Thanks.

“buy price for GSK 1783.4” => This is the closing price of GSK on 19 July. I sold and bought at this price.
“cost price for HLN 356.68” => Simply 1783.4 / 5 since for every 0.2 share of GSK but got a share of HLN

Will it affect my cost price after i approve the event? What will i expect to see after approval? Sorry i am abit confused =.="

I was thinking after the event, my cost should not change. 692 GSK shares cost the same.
For HLN, the cost will be 173 shares (865-692) of GSK x 1,371.25 each = 237226.25. Each HLN share cost 274.25. Is this correct?

No problem.

Yes, in this case, it will change your cost because the profit/loss will already be reflected in the event when we sell GSK.

In this case, it is better for you to handle the event yourself since I cannot set it as a global event as everyone would have different cost.

You basically need to create 3 transactions.

  1. Sell GSK at your original cost (in your case sell 865 units at GBX 1,371.25 on 19th July)

  2. Buy 0.8 shares of the original amount of GSK (in your case buy 692 units at GBX 1,371.25 on 19th July)

  3. Buy 5x shares of HLN of the original amount of GSK units (in your case buy 865 units at GBX 274.25 on 19th July)

This will preserve your cost.