Leading brokerage firm Indiabulls Financial Services has raised $275 million through a global depository receipt (GDR) offering, and will list the securities on the Luxembourg Stock Exchange.Indiabulls Financial Services priced its offering at $13.06 per GDR, and each GDR represents one equity share of the company with a face value of Rs 2 each, the company said in a release issued to the BSE today.