Senco Gold Limited’s Rs 405 crore initial public offering (IPO) opens for public subscription today. The Kolkata-based company is a renowned pan-India jewellery retailer incorporated in 1994. It will be the first IPO opening for subscription in the second half of the year. The shares have started trading in unlisted stock market and are available at a premium of of Rs 102 in grey market today, according to market observers.