Major US indices were up more than one percent, with analysts citing economic stimulus measures by the People's Bank of China as cushioning the blow in that country, as well as the extremely limited spread of the ailment so far in the United States.
About 15 minutes into trading, the Dow Jones Industrial Average stood at 28,787.41, up 1.4 percent.
The broad-based S&P 500 gained 1.2 percent to 3,289.00, while the tech-rich Nasdaq Composite Index advanced 1.3 percent to 9,397.35.
The gains early Tuesday added to the February advance after Friday's rout on rising fears that the virus outbreak would derail global growth.
But a note from Charles Schwab pointed out that, based on past disease outbreaks, a "short-term dip in stocks tended to be followed by the continuation of the upward trend."
Among individual companies, Tesla continued to rocket higher, adding another 12.6 percent after jumping nearly 20 percent Monday following a run of strong results.
Google parent Alphabet slid 3.7 percent after reporting fourth-quarter sales that missed expectations despite stellar growth at YouTube and in their cloud-oriented businesses. jmb/cs