The stock nosedived 10.02 per cent to settle at Rs 643.85 on BSE. During the day, it plunged 17.46 per cent to Rs 590.60.
On NSE, shares of the company tumbled 10.21 per cent to Rs 643.50.
The company's market valuation declined by Rs 2,919.23 crore to Rs 27,078.77 crore.
The announcement was made yesterday when the domestic bourses were closed for Diwali.
The company said the acquisition will help it chart a roadmap to a deposit-taking franchise.
More From This Section
"...The company will be the largest shareholder in the bank," Indiabulls Housing said in a regulatory filing yesterday.
It further said: "Sameer Gehlaut, Chairman of the company, will be investing in his personal capacity up to 10 per cent stake in OakNorth Bank at the same valuation."
In the broader market, the Sensex lost 256.42 points to 25,610.53.