Defence spending has hit the headlines in recent months, particularly following the surprise election victory of US President Donald Trump.
Shares in BAE Systems fell 10% today after the aerospace giant issued a profit warning.
Managers have been buying in to aerospace companies as firms in the sector begin to see large orders coming from the Middle East.
British defence giant BAE has started a three-year share buyback programme of up to £1bn, despite reporting declines in full year pre-tax profits and revenues.
Barry Norris, founding partner and chief investment officer at Argonaut Capital Partners, has said the collapse of the BAE/EADS merger today is a "triumph for common sense."
Opposition from politicians and investors including Invesco Perpetual has led defence giants BAE and EADS to scrap their proposed merger.
Shares in UK defence contractor BAE Systems reversed a late rally last night to fall 9% this morning, after announcing it was in talks with European peer EADs about a merger.