Meet Masa Son - the "crazy" Vision Fund founder backing WeWork and Uber

After spectacular early successes backing AliBaba and Yahoo, Softbank's Masayoshi Son raised $100bn from investors in a matter of weeks. The Korean-Japanese behind the revolutionary VisionFund spent this money almost as rapidly, pumping billions into WeWork, Uber and their lookalikes - alongside unorthodox bets like $300m injected in to a dog-walking app. Son is on his way to raising another $100bn in Vision Fund II, claiming that he already has more than that committed by his fans.  But critics are fretting that having too much money is making Son reckless, typified by WeWork's attempted IPO where investors rejected the $47bn valuation at which Son was happy to inject billions. Have a listen to this fascinating podcast from our partners at the Wall Street Journal.