Finance: Billionaire Michael Dell was just revealed as the mysterious buyer of the most expensive home ever sold in NYC, a $100 million penthouse — see inside

Michael Dell’s penthouse in the Manhattan luxury building is the first and only New York apartment sale to surpass $100 million.

Finance: Silicon Valley is so expensive that people who make $400,000 think they’re middle-class — here’s what the middle class actually is in the 25 largest US cities

Middle-class incomes in the US were between about $39,000 and $118,000 in 2016, but the ranges shift at the state and city levels.