NEW YORK, Dec 28 — The S&P 500 was on track to open at all-time highs today, building on a record-setting rally amid thin trading volumes, with investors unshaken by Omicron-driven travel disruptions and store closures.

The S&P 500 and Nasdaq yesterday posted their best four-day rally since November 2020, with the S&P 500 scaling a peak as an upbeat outlook on the US economy helped investors look past thousands of flight cancellations and Apple Inc shutting its New York stores due to surging cases.

The Centres for Disease Control and Prevention (CDC) yesterday shortened the recommended isolation time for Americans with asymptomatic cases of COVID-19 to five days from the previous guidance of 10 days.

The CDC’s update along with approvals to new pills and more vaccines to fight COVID-19 have all helped put the three main indexes on pace for monthly gains.

“This policy change is sending the message that it is becoming more like the flu and less like the variants we saw early on when we had no treatments, no vaccines and it was much more deadly,” said Thomas Hayes, managing member at Great Hill Capital in New York.

At 8:16 a.m. ET, Dow e-minis were up 77 points, or 0.21 per cent, S&P 500 e-minis were up 11 points, or 0.23 per cent, and Nasdaq 100 e-minis were up 70.5 points, or 0.43 per cent.

Some megacap companies have roared in the recent rally, with Tesla Inc jumping 1.7 per cent in premarket trade after surging nearly 22 per cent in value over the past four sessions. Apple , which is up marginally, is within spitting distance of becoming the first US company to hit $3 trillion in market capitalization.

Chipmakers Nvidia Corp, Advanced Micro Devices Inc and Qualcomm Inc all firmed 0.6 per cent-1 per cent.

Markets are in one of the seasonally strong periods, also called the Santa Claus Rally, with CFRA Research data showing the S&P 500 has on average risen 1.3 per cent in the last 5 trading days of the year, and first two days of the new year since 1969. (Reporting by Medha Singh and Bansari Mayur Kamdar in Bengaluru; editing by Uttaresh.V)