US stock index futures scaled all-time highs on Tuesday as bets that fiscal aid will speed up a vaccine-led recovery in the economy boosted sentiment in the final days of the year.
At 06:34am Eastern Time, Dow E-minis rose 129 points or 0.43 per cent, S&P 500 E-minis gained 16 points or 0.43 per cent and Nasdaq 100 E-minis added 46.25 points or 0.36 per cent.
Wall Street's main indexes ended at all-time highs on Monday, with pandemic-battered stocks leading the gains after US President Donald Trump signed a long-awaited $US2.3 trillion ($A3 trillion) fiscal bill, restoring unemployment benefits to millions of Americans and averting a federal government shutdown.
Unprecedented monetary as well as fiscal stimulus and positive vaccine data have helped the S&P 500 recover from a virus-led crash in March.
The benchmark index is looking at its best fourth-quarter performance since 2011 as investors returned to economically sensitive stocks from the so called 'stay-at-home' plays on hopes of economic recovery.
The Democratic-led US House of Representatives on Monday approved a proposal to increase the COVID-19 payment cheques to $US2,000 ($A2,633) from $US600 ($A790), sending the measure for a vote in the Republican-controlled Senate on Tuesday, where it faces a much tougher path for approval.
Trading volumes is expected to remain light in a historically strong final week for equities, with worries over a mutating coronavirus strain and upcoming US Senate runoffs in Georgia posing as short-term concerns.
Shares of planemaker Boeing Co added 0.6 per cent in pre-market trade as American Airlines was set to restart US 737 Max commercial flights on Tuesday morning.