Under the London Stock Exchange listing rules if the the directors have any indication that trading or some other event may have a material affect on the share price they are obliged to disclose it within two days. As the share price has been in declime for much longer than that and there has been no statement then I think we can assume that there are no nasties.
I think it is just sentiment. Fund managers and other institutional buyers are being very conservative at present and are just not buying shares in what they regard as risky technology companies.