The Nasdaq Composite (NASDAQINDEX:^IXIC) continued to lose ground on Thursday, adding to a pullback over the last few days that has taken the steam out of the tech-heavy benchmark's advance since mid-September. Market participants aren't getting all the support they think they deserve from government policymakers, and the result was an across-the-board decline for major indexes. Having risen the furthest, the Nasdaq had the furthest to fall, and it was down almost 1% as of 2 p.m. EDT.

Playing a sizable role in pulling down the market, Nasdaq-100 member Vertex Pharmaceuticals (NASDAQ:VRTX) took a big hit on bad news from its drug pipeline. Meanwhile, Zoom Video Communications (NASDAQ:ZM) continued to move higher as those following the video conferencing disruptor are getting even more optimistic about its long-term prospects.

Feeling the pain at Vertex

Vertex Pharmaceuticals saw its shares drop nearly 20% on Thursday afternoon. The drug company made an announcement on a promising candidate treatment for a rare disease that disappointed investors.

Needle poking cell under magnification.

Image source: Getty Images.

Vertex had been hoping that its VX-814 drug would be able to treat a disease called alpha-1 antitrypsin deficiency. The disease is inherited based on genetic profile, and it can cause damage to the liver and lungs, resulting in lung diseases such as emphysema as well as jaundice and advanced liver disease.

A phase 2 study had been looking at patients suffering from this disease, but Vertex had to discontinue that study based on safety indicators and early data on the patients' reactions to the drug. With elevated liver enzymes appearing, Vertex decided no longer to pursue treating the disease with VX-814.

Vertex does have another candidate drug, VX-864, that it hopes will prove more promising. A phase 2 trial is ongoing with that treatment with data expected in the first half of 2021. For now, though, investors are mourning the loss of a hoped-for solution to a rare genetic disease.

A clear vision at Zoom

Elsewhere, shares of Zoom Video Communications climbed another 5%, pushing to an all-time record high. The video collaboration specialist has gotten a lot of positive attention from Wall Street, and the praise continued on Thursday.

Multiple stock analysts boosted their views on Zoom's stock. The most aggressive move came from Bernstein, which pushed its price target up from $228 per share to $611. Other increases included a $50 rise at BTIG to $550, a $140 boost from DA Davidson to $600, a $90 rise at Wells Fargo to $465, a $150 hike from RBC Capital to $600, and a $90 increase from Piper Sandler to $501 per share.

The moves came after promising announcements at Zoom's investor day. Zoom intends to continue coming out with new products to enhance and complement its video collaboration platform, including its Zoom Phone service. But it's also being prudent about not going beyond its core competency. In particular, investors seemed to like the idea that Zoom won't try to go up against Slack Technologies and Microsoft by building out a chat service to go with its video platform. Instead, the company appears to be ready to pursue partnerships with other tech companies as appropriate.

Zoom has already seen amazing share-price growth in 2020, but investors keep hearing things they like from the company. If that continues, further gains could be in store for Zoom.

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