I think the price drop was a massive over-reaction, but what do I know? MMs making the most of an opportunity, I guess. According to the fundamentals, DYS last pre-tax profit was 5.83 million, if that drops to a mere 5 million, I don't see that as adequate cause for a 16% price drop.
Also I am bearing in mind that the very reason quoted for the profit warning, price of energy, is likely to enhance certain of the markets to which DYS is exposed, namely fuel cell technology. How much that market will change, I have no idea but I am still comfortable holding the stock.
No advice intended, just my personal viewpoint.