Shares in Jarvis Securities shot up on Monday after the stockbroking firm said that the significant growth seen in its retail stockbroking business last year continued in the first quarter of 2010.Trade volumes were up 71% year on year while active client numbers at the end of March 2010 stood 44% higher than end-March 2009.Total assets under administration at the end of March 2010 were 22% higher than a year earlier."We have also noted a significant improvement in deposit rates for cash since the start of the year and as older deposits mature we will see strong growth in our interest income from the current depressed levels," said Andrew Grant, chairman and chief executive of Jarvis.