How investors should respond to tech valuation risks

In a BBC interview, the head of America's largest bank, J P Morgan, has warned that US stock markets do not currently reflect the level of risk of a serious fall. Jamie Dimon said he was "far more worried than others" about a major market correction. China has tightened its rules on the export of rare earths – the elements that are crucial to the manufacture of many high-tech products. And the price of silver hit its highest level in decades. The metal reached more than $50 an ounce. Presenter: Sarah Rogers Producer: Ahmed Adan Editor: Justin Bones