Vistra Energy ( NYSE: VST ) may not be a familiar sounding name to most people, but almost everyone knows something of how Vistra came to be a stand-alone power producer. Vistra was originally comprised of the power generation and retail portion of TXU Corp. TXU was acquired in a leveraged buyout led by KKR in 2007, in what was a record size of a LBO at the time. Renamed Energy Future Holdings, the deal was a bet that power prices and natural gas prices would continue to rise in the coming years. Unfortunately for Energy Future Holdings and its private equity owners, horizontal drilling and fracking were about to open up vast new reserves of natural gas, collapsing prices of the fuel that typically provides that marginal cost of electricity and therefore, collapsing the price of electricity. A 2014 bankruptcy eventually lead to Vistra being carved off and returning to the public markets, first as an over the counter stock, and eventually on the New York Stock Exchange in May 2017.