TOKYO -- As an advertisement for an asset class, Tesla's announcement this month that it would convert a sizeable chunk of its cash reserves into bitcoin seemed to be as good as it gets.
After all, here was the world's richest man, Elon Musk, backing a plan to put $1.5 billion of his company's money into the cryptocurrency. And many investors took the view that what is good enough for Musk and his electric vehicle and clean energy company is good enough for them.
