New York CNN  —  Millions of Americans have watched their net worth spike since the pandemic, powered by meteoric gains in the stock market. Wall Street’s blockbuster returns — the strongest back-to-back years since the boomy Clinton years of the late 1990s — have boosted confidence and encouraged consumers to keep spending at will. Now, there are growing worries in some corners that things may be getting out of hand, that the price tag on some stocks has become untethered from reality. The