The last two scenarios when U.S. stocks went up this quickly? During the dot-com bubble and after recessions.

The historic stock-market rally has shown few signs of stopping since October — with the S&P 500 advancing in 16 of the last 18 weeks for the first time since 1971. There have been only two other scenarios when U.S. stocks climbed this fast over any four-month period since World War II, and the recent rally has “strong parallels” to both, according to a Deutsche Bank analyst.The first scenario was when the economy was emerging from recession, such as after the COVID-19 pand