The Nasdaq Composite index tumbled at the open on Thursday, dropping more than 20 percent from its record closing high in November last year and on track to confirm a bear market, after Russia launched an all-out invasion of Ukraine. The Dow Jones Industrial Average fell 301.43 points, or 0.91 percent, at the open to 32,830.33, falling more than 10 percent from its all-time closing peak on Jan. 4 and on pace to confirm a correction. The S&P 500 opened lower by 69.73 points, or 1.65 percent, at 4,155.77, while the Nasdaq Composite dropped 449.61 points, or 3.45 percent, to 12,587.88 at the opening bell. A correction and a bear market are confirmed when an index closes down 10 percent and 20 percent or more, respectively, from its record closing level. By Susan Mathew and Devik Jain