If investors ever needed a clear signal that this is the top of the market, they now have one. Walgreens Boots Alliance shares surged Wednesday after speculation that the U.S.-listed drugstore group has been considering a $70 billion take-private deal. If private equity can pull it off, it would be the biggest-ever leveraged buyout, dwarfing the $45 billion take-private transaction of energy group TXU in 2007, which occurred just a year before the financial crisis rocked global markets and prompted unprecedented intervention by global central banks.
