Investment in defence tech start-ups has reached a record high this year as the world’s biggest arms companies step up spending on new military technology. New figures from Dealroom show defence contractors including BAE Systems, Lockheed Martin and Airbus have participated in $4.1bn (£3bn) of venture capital funding rounds so far this year, the highest figure on record. Meanwhile, separate research from White & Case found 42 defence mergers and acquisitions were completed globally in the first half of 2026, up 56 per cent from…