John Authers analyses a nervous day on world markets as stocks sold off. Beyond the sharply negative reaction to the latest moves on US immigration by President Trump, there were also of political uncertainty in Europe.<br /><br />► Subscribe to FT.com here: http://on.ft.com/2eZZoLI<br /><br />► Subscribe to the Financial Times on YouTube: http://bit.ly/FTimeSubs<br /><br />For more video content from the Financial Times, visit http://www.FT.com/video<br /><br /><br />Twitter https://twitter.com/ftvideo<br />Facebook https://www.facebook.com/financialtimes