It would seem that yesterday's RNS reporting Final Results for the year to 31 May 2015 was deemed to be sufficiently positive by someone to invest almost one million GBP of their hard-earned... 
http://www.lse.co.uk/ShareTrades.asp?shareprice=FDEV&share=frontier_dev
http://www.lse.co.uk/ShareTrades.asp?shareprice=FDEV&share=frontier_dev