AIM-listed Octagonal, which holds close to a 10% stake in custody and clearing company Global Investment Strategy (GIS) UK as its main investment, has reported a strong operational performance by GIS for both April and May. During the two months, the total settled transactions surpassed 12,000, with the settlement values exceeding £1.6bn. GIS, in which Octagonal bought its stake in April, has launched a mini prime broker service for its global hedge fund clients and has appointed an investment advisor for the Seachange Capital Absolute Fund, a Cayman Islands-incorporated fund specialising in on-exchange option trading.Shares in Octagonal, which changed its name from SureTrack Monitoring in November 2013 after a company reorganisation, had jumped 29.87% to 0.487p by 09:27 on Wednesday.NR