Mumbai: The activity in the primary market has picked up of late boosted by the rebound in equities in the past two months. Go Digit General Insurance, Concord Biotech, an Ahmedabad-based firm backed by RARE Enterprises, and Kolkata-based Balaji Solutions have filed their draft red herring prospectus (DRHP) with the markets regulator Securities and Exchange Board of India (SEBI), on Tuesday to launch the initial public offerings. These three companies could collectively raise around ₹7,500 crores through IPOs.