(ShareCast News) - Investment fund BlueCrest AllBlue posted a rise in net asset value in the first six months of the year, although volatility in the financial markets weighed on the performance.In the six months to 30 June, the FTSE 250 group said its net asset value per share increased 0.8%, although it described the "modest gain" as a disappointment after the "good returns" it reported in the corresponding period in 2014.The slower-than-expected increase was attributed to geo-political tension in Russia and the Middle East, the financial crisis in Greece and the loss of momentum in the Chinese economy."In order to remain an attractive investment, the company must not only exhibit tight risk controls and diversification benefits in portfolios but must also generate attractive returns," said group chairman Richard Crowder.However, Crowder added that the increasing volatility of fixed income markets was beginning to generate "good opportunities" for the company.BlueCrest shares were down 0.53% to 189.00p at 1543 BST on Thursday.