The tech-heavy index on Monday closed down 2.22% unofficially at 12,633.61, roughly 10.6% below the Feb. 12 record close at 14,095.47 and exceeding the 10% closing-basis threshold considered by market professionals as confirmation of a correction. The Nasdaq entered the latest bull market last March and rose more than 105% from the pandemic low a year ago.

Market-leading tech and tech-adjacent megacap stocks, which account for much of the Nasdaq's total market value, thrived during the pandemic recession. But many of those shares are now seen by some investors as overvalued.

More cyclical stocks, which were battered by shutdowns and stand to benefit most from economic recovery, have since gained favor as vaccine deployment gathers steam and restrictions are lifted.

For the year, the Nasdaq is down 2.2%, while the S&P 500 and the Dow are up 1.7% and 3.9%, respectively.

(This story corrects start date and percent gain of bull market in paragraph 2)

(Reporting by Stephen Culp; Editing by Alden Bentley)