After a stock split, the new shares will be added to your Demat account in 3 to 4 working days after the record date.
Until the split shares are credited to your Demat, your holdings in the Upstox app will show an artificial drop in P&L. Once the split shares are credited to your Demat, your P&L will be restored to its correct value.
If it has been more than 4 days from the record date and you still haven't received the split shares even though you are eligible for it, raise a ticket and our customer support representative will get back to you shortly.
To Know in detail about stock split please click on the below link.