It’s what Paul McCartney might call “hands across the water,” the capitalist chapter, anyway. One of Wall Street’s most famous hedge fund captains has his sights set on one of London’s biggest asset managers. Nelson Peltz’s Trian Fund Management and venture capital firm General Catalyst offered to acquire the UK’s Janus Henderson at a roughly $7.2 billion valuation on Monday. Trian, which already owns 20.4% of the asset manager, said it would be better off as a private company. Janus Henderson, which over ...