India's biggest solar module manufacturer Waaree Energies' ₹4,321 crore IPO is open for subscription from October 21-23 at a price band of ₹1,427-1,503 per share. Investors can bid for a minimum of 9 shares, requiring an investment of ₹13,527. Ahead of the listing, unlisted shares of the company were reportedly trading at a premium of 100% in the grey market.