Yahoo Finance's Myles Udland and Seana Smith discuss the markets big losses today. Stocks plunged Thursday, as Wall Street gave back gains after capping off yet another record-setting session a day earlier. The Dow slid more than 944 points, or 2.5%, as of 3:03 p.m. ET. The broader market sold off, with the S&P 500 down 4% and the Nasdaq down more than 5.5% as big tech shares including Amazon (AMZN), Apple (AAPL), Microsoft (MSFT) and Facebook (FB) each sold off. While there was no immediate trigger, the session’s moves represented a stark reversal from the bullish tone seen at the beginning of this week. The selloff “could very well be the start of the inevitable Nasdaq correction, but no one has any way of knowing that,” noted David Bahnsen, chief investment officer, California-based The Bahnsen Group. “So far, the move downward is rather hum-drum and immaterial.” He added that a pullback was “understandable” given that “The Nasdaq has advanced violently since March and many names are at absurd valuations.” Both the S&P 500 and Nasdaq ended the regular session Wednesday at their highest-ever closing levels. The broad rally lifted stocks and sectors that had been underperforming so far during the pandemic, with the utilities, materials and real estate sectors leading advances in the S&P 500 on the day. The Dow spiked above 29,000 for the first time since February and came within 500 points of its all-time record level, before sharply reversing these gains on Thursday. The jump earlier this week came as investors continued to bet on a protracted era of accommodation from the Federal Reserve and other global central banks as policymakers work to offer ongoing support the virus-stricken economy. Hopes that a coronavirus vaccine will be available in the near-term – and thereby allow more businesses to reopen and consumers to spend more confidently – have also supported equities. Media outlets including Bloomberg reported Wednesday that the U.S. Centers for Disease Control and Prevention has told states to prepare for a Covid-19 vaccine that would be ready for distribution by the beginning of November. Subscribe to Yahoo Finance: https://yhoo.it/2fGu5Bb About Yahoo Finance: At Yahoo Finance, you get free stock quotes, up-to-date news, portfolio management resources, international market data, social interaction and mortgage rates that help you manage your financial life. Connect with Yahoo Finance: Get the latest news: https://yhoo.it/2fGu5Bb Find Yahoo Finance on Facebook: http://bit.ly/2A9u5Zq Follow Yahoo Finance on Twitter: http://bit.ly/2LMgloP Follow Yahoo Finance on Instagram: http://bit.ly/2LOpNYz Follow Cashay.com