Shares in Shoreditch-based start-up firm LoopUp were up over 10% on its first day of trading on AIM, London's junior market. The conference call start-up listed with a market cap of £40.8 million after raising £8.5 million. Boss Steve Flavell said: "The completion of the IPO process marks an important and exciting milestone on LoopUp's journey. The reception from investors has been positive and encouraging, and reinforces our belief that our differentiated product, business model and plans for the future provide the foundation needed."