Despite staging a three-day rally late last week, U.S. stock-index futures fell on Sunday in line with some analysts' predictions that a convincing rebound of the markets from the coronavirus pandemic may yet to take place.

David Bach, the deputy dean of Yale School of Management, told CGTN last Friday that any rally that is being seen in the stock markets may be a "false bottom," as the U.S. government's latest stimulus measures may not be enough.

"[The U.S.'s] 2.2 trillion aid package is good, but most analysts believe this is a stop-gap measure, and it's going to help for about three months or so," said Bach, adding that such an amount may be adequate if the pandemic peaks in accordance with U.S. President Donald Trump's earlier "by Easter" prediction. Easter falls on April 12, but on Sunday, Trump extended social-distancing guidelines through April 30.

"Of course, if you're like the [U.S.] president that much of this is over by Easter, then perhaps that's good news and that's a rally.

"But most epidemiologists here and around the world think this is going to be a larger phenomenon, the peak is going to be later and the economic impact is going to be more severe," Bach said.

"And I think people are soon going to realize that. As big as this 2.2 trillion aid package is, it won't be sufficient. And as soon as markets realize that, of course downward pressure is likely going to resume," he added.

U.S. stimulus 'not enough'

Last Friday, Trump signed an unprecedented 2.2-trillion-U.S.-dollar economic rescue package into law in an effort to support businesses, healthcare providers and families during the COVID-19 crisis. It is said to be the largest in history.

Stocks were lifted mid-week in anticipation of the stimulus package from the U.S. Federal Reserve and global central banks have also responded with an aggressive array of monetary policy measures.

However, several investors and economists in a Reuters report cast doubts over whether the U.S. government's measures were sufficient to dampen the disruption from the outbreak. In a research note last week, Bank of America analysts said the aid package passed last week was the "bare minimum," estimating that three trillion U.S. dollars or more may be needed if the recession deepens. Scott Minerd, chief investment officer at Guggenheim Partners and member of an investor committee that advises the New York Federal Reserve on financial markets, told Reuters he believes the government needs to give the Treasury about two trillion U.S. dollars to help prop up the economy.

Meanwhile, JPMorgan strategists on Friday said that most risk assets – a universe that typically includes stocks and credit – have seen their low points and the conditions for market stabilization are being met.

The U.S. now has the world's highest number of confirmed cases, overtaking Italy and China last week. The total number of cases in the U.S. exceeded 140,000, while the total tally worldwide is now over 720,000, according to data by Johns Hopkins University.