If you have a seven-figure net worth but don’t really consider yourself wealthy, you may be part of a growing population of "hidden millionaires." Vanguard applies the term to Americans who have quietly passed the million-dollar mark in recent years, primarily through saving for retirement and building home equity. "Last year, we saw over 127,000 retail investors who became millionaires," said Andy Reed, head of investment behavior research at Vanguard. "Every day on our platforms, there are hundreds of ...