Traders work on the floor at the New York Stock Exchange.

Brendan McDermid | Reuters

This is a live blog. Please check back for updates.

12:27 pm: Gundlach blames Bernie Sanders for sell-off

“If the stock market reversal is due exclusively to the virus then why is United Healthcare down far more than the S&P? Why is healthcare as a sector broadly not outperforming? Answer to those questions: the market is digesting a better than 50% chance of Bernie Sanders getting the nomination,” Jeffrey Gundlach, DoubleLine Capital CEO and Wall Street “Bond King,” wrote in an email to CNBC’s Scott Wapner on Wednesday. – Fitzgerald

12:22 pm: Dow jumps triple digits

Almost immediately after turning negative, the Dow reversed course to turn positive again, jumping more than 100 points in quick succession as the market digests the latest coronavirus headlines. – Stevens

12:18 pm: Dow turns negative

The Dow turned negative, giving back its earlier gain of 461 points. – Stevens

12:16 pm: 10-year Treasury yield rolls over

The 10-year Treasury yield turned lower, hovering near its all-time low, as investors remained on high alert about the deadly coronavirus. The benchmark yield, which moves inversely to price, fell one basis point to around 1.324% around midday. The rate was about 3 basis points higher earlier in the session. Yields erased early gains even after data showed new home sales jumped to the highest level since 2007. – Li

12:10 pm: Stock rally fades

The Dow has given back a large portion of its early gains and is now up just 61 points, or 0.2%, as the U.S. Food and Drug Administration said the coronavirus is on the cusp of a becoming a pandemic. The S&P 500 is up 0.2% and the Nasdaq is up 0.5%. – Stevens

11:52 am: Markets at midday: Stocks try to make up lost ground from massive 2-day sell-off

Around midday, the major U.S. stock averages were trading sharply higher as they recovered some of the steep losses suffered in the previous two sessions. The Dow is up more than 300 points, or 1.2%. The S&P 500 and Nasdaq are also up more than 1% each. Those gains come after the S&P 500 had its worst two-day stretch in more than four years. —Imbert

11:39 am: Morning rally may fade, technical analyst says

Frank Gretz, a technical analyst at Wellington Shields, said he doesn’t think the market has reached a bottom yet and is not a believer in this morning’s rally. “I never like to see the market open higher when it’s been in a downturn. I’d rather see them hit them at the beginning and then rally in the afternoon,” Gretz said. “So I’m a little skeptical about today on that basis. I’m a little skeptical because I don’t think we’re quite to all the extremes we need in terms of making a bottom, but we’re getting there.” — Pound

10:48 am: Biotech Moderna hits record high on vaccine efforts

Moderna surged more than 20% to hit an all-time high, after gaining 27.8% just on Tuesday. The rally came after the biotech company said it had shipped a coronavirus vaccine to U.S. government researchers for study. Moderna is hoping for a clinical trial by the end of April. The company went public on Dec. 7, 2018 at $23 per share and is up 26% from its IPO price. —Francolla, Li

10:44 am: Apple and Netflix rebound

Shares of Apple popped more than 3% in morning trading, continuing the stock’s rebound out of correction territory. Apple through Tuesday was down 12% from its recent high on worries about the impact of the coronavirus on its quarterly revenue. Shares of streaming platform Netflix rallied more than 5%, after dropping more than 2% on Tuesday. –Fitzgerald

10:13 am: Don’t buy this bounce, says Canaccord Genuity

Canaccord Genuity’s Tony Dywer weighed in before the market open on the potential for a pop like the one we are seeing Wednesday. “Expect pop then [a] test of the low. We have seen this before – maybe not the COVID-19 virus – but an event that puts global growth into question and creates an extreme selloff,” wrote Dywer in a note. “The recent history of such dramatic market swoons reinforces our view the market is likely to see a sharp oversold rally that could be relatively significant but ultimately temporary.” — Melloy

10:00 am: Bank of America still cautious on sell-off

Bank of America does not think it’s quite time to step in just yet. Savita Subramanian, the firm’s chief U.S. equity and quant strategist, said she’s “still neutral, but if correction continues, buy” in a note. Subramanian is maintaining her S&P 500 3,300 year-end target, which is about 4% higher from where it is now. But the strategist notes that technical factors and supply chain disruptions from the coronavirus suggest the washout has a little further to go. She also said that the Treasury market is pricing in 50 basis points of Fed rate cuts this year.— Melloy

9:45 am: Cramer says investors should put some cash to work

CNBC’s Jim Cramer said he is now less negative about the coronavirus and suggested investors put cash to work Wednesday. “I came into this thing hating things. I don’t hate them as much,” he said, citing the recent comments about a potential vaccine from Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. “Let’s say you have 20% cash, you’re not going to put 1% to work?” Cramer said. — Stankiewicz

9:42 am: Market comeback gains steam with Dow now up 300 points

The Dow quickly added to its gains in morning trading, now up 315 points, rebounding from a brutal sell-off earlier this week. Big tech is leading the comeback, with Microsoft and Netflix rising 2.2% and 3.2%, respectively. Apple rose 1.4%, after dipping into correction territory in the previous session.— Li

9:31 am: Dow rises 150 points, rebounding from 1,900-point sell-off

The Dow climbed about 150 points at the open, recovering a fraction of the losses from this week’s monster stock rout. The 30-stock benchmark plunged 1,900 points in just two days amid increasing fears about the coronavirus. The S&P 500 posted back-to-back losses of more than 3%, suffering its biggest two-day drop since 2015. Traders will look for more updates on the epidemic for signal, including a briefing from President Donald Trump this evening.— Li

9:24 am: Here are Wednesday’s biggest analyst calls of the day

8:48 am: After 2-day declines this extreme, the Dow tends to bounce, history shows

In the last two sessions the Dow has shed 6.59% — its worst two-day performance since Feb. 2018 — but history shows that two day drops of this magnitude are typically a sign that negative sentiment has become too extreme, too quickly. Looking at performance over the last 30 years, data analytics tool Kensho found that following a drop of more than 6% over two consecutive sessions, 75% of the time the index rallied over the next two weeks, and 88% of the time it rallied over the following month. Outside of the financial crisis, the Dow was higher one month later in every single instance. — Stevens

8:40 am: Apple hovers around breakeven after falling into correction territory

Shares of Apple are flat in premarket trading after the tech giant dipped into correction territory on Tuesday. Shares have slid 10.98% in the last week as the rising number of coronavirus cases outside of China has spooked investors. In the last four trading sessions Apple has erased $140 billion in market value. Earlier in February the company said it does not expect to meet its prior revenue guidance due to the impact from the coronavirus. — Stevens

8:33 am: Dow futures up 100 points

Futures on the Dow Jones Industrial Average now rose 100 points, indicating a near 150-point higher open. Stock attempt to come back from its worst two-day rout since 2015. The S&P 500 posted its first back-to-back losses of more than 3% in more than four years, while the Dow has tumbled 1,900 this week on coronavirus fears. — Li

8:30 am: Trump to hold news conference at 6 pm

President Donald Trump tweeted on Wednesday he will hold a news conference Wednesday at 6 p.m. to address concerns over the coronavirus outbreak. His tweets came after The Washington Post reported Trump was furious that the stock market was being battered by worries over the coronavirus. —Imbert

8:22 am: Bank shares rise slightly along with Treasury yields

Bank stocks are trading slightly higher as Treasury yields climb from the low levels seen in the previous session. Bank of America and JPMorgan Chase are up 0.2% and 0.4%, respectively, in the premarket. Citigroup and Morgan Stanley are gaining 0.3%. The 10-year Treasury yield is trading at 1.364% after falling to a record low on Tuesday. Lower yields put pressure on banks’ profit margins. —Imbert

8:20 am: Big trading volumes amid sell-off

One of the few beneficiaries of the two-day selloff: huge trading volume. CME (futures) reported record volumes yesterday. CBOE (options, VIX) saw the heaviest day of trading in VIX futures since October 2018, according to Piper Sandler. NYSE volume was 50% higher than normal. Watch market maker Virtu, up 11% this month, which benefits during periods of high trading and volatility. —Pisani

7:59 am: 10-year Treasury yield rebounds from all-time low

The 10-year Treasury yield climbed on Wednesday, after sinking to an all-time low as investors sought the safety of U.S. government debt amid heightened fears about the fast-spreading coronavirus. The benchmark yield, which moves inversely to price, rose three basis points to 1.359%. The 2-year yield, however, hit a low of 1.157% on Wednesday, its lowest level since Feburary 2017. The short-duration rate is the most sensitive to Federal Reserve’s monetary policy expectations. Traders have increasingly priced in a rate reduction at the central bank’s April meeting. —Li

7:56 am: 3-day slide is 25th worst since 1950

UBS notes that the 7% decline in the S&P 500 in three days is the 25th worst since 1950. Strategist Keith Parker believes that stocks are likely to remain volatile over the coming weeks as coronavirus cases outside of China increase, companies lower earnings forecasts and U.S. election primaries cause uncertainty. “Valuation is supportive and growth in Q2 is expected to rebound, but risks remain,” the strategist wrote in a note. Parker is advising clients to buy quality and momentum stocks, which tend to outperform in the two months following volatility shocks. —Melloy

7:47 am: Analysts surprised by the Disney CEO switch

Disney shares fell as analysts tried to make sense of Bob Iger’s move into the executive chairman role with Bob Chapek taking over as CEO. “This is negative for DIS as DIS’s EPS weakness is riskier without Iger’s value-creating track record,” Needham analyst Laura Martin said. “There is never a great time for succession announcements, but this one is likely to cause particular consternation with investors,” Wells Fargo analyst Steven Cahall said. CNBC PRO subscribers can read more here. —Bloom

7:20 am: Disney shares fall 2% as CEO Bob Iger steps down, effective immediately

Shares of Disney fell more than 2% during Wednesday’s premarket trading after the company said that CEO Bob Iger would step down, effective immediately, and assume the role as executive chairman. Bob Chapek, who most recently served as chairman of Disney parks, experiences and products, will become the company’s new CEO. He will be the seventh CEO in Disney’s nearly 100-year history. “I obviously have huge shoes to fill,” Chapek told CNBC’s Julia Boorstin on “Closing Bell” Tuesday. “Bob’s legacy in the company is just profound. I think my role is not to take the strategic pillars he’s so well established over the last 15 years and continue to work on those and implement those in the marketplace, most importantly our direct-to-consumer initiatives, but at the same time look around the corner for what disruption might be going on in the marketplace that would necessitate a fresh look at those things.” —Stevens

7:16 am: Coronavirus cases jump

South Korea reported 169 new coronavirus cases overnight, bringing the country’s total to more than 1,100. The number of coronavirus cases in Italy has broken above 300, with some being reported outside of the original epicenter in the north. Meanwhile, China confirmed 406 new cases along with 52 deaths. —Imbert

7:15 am: Stock futures flat as Wall Street tries to rebound from back-to-back massive losses

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