Stocks making the biggest moves in the premarket: Moderna, Casper Sleep, Uber, Tapestry & more
Take a look at some of the biggest movers in the premarket:

Moderna (MRNA) – The drugmaker said the first analysis of phase 3 study data showed its experimental Covid-19 vaccine had an efficacy rate of 94.5% and saw no significant safety concerns. Moderna also said the vaccine will stay stable at refrigerated temperatures for 30 days, up from a prior estimate of 7 days. Shares of Moderna jumped nearly 15% in premarket trading.

Casper Sleep (CSPR) – Casper Sleep lost 40 cents per share for the third quarter, wider than the 33 cents a share loss that analysts were expecting. The mattress and bedding maker's revenue came in short of estimates, hurt by Covid-related supply chain disruptions. Shares of Casper slid more than 11% in the premarket.

Palo Alto Networks (PANW) – The cybersecurity company earned an adjusted $1.62 per share for its latest quarter, compared to a consensus estimate of $1.33 a share. Revenue topped estimates as well. Palo Alto also raised its full-year earnings and revenue forecast, with the company saying product enhancements are boosting demand. The company's shares rose 2% in premarket trade.

JD.com (JD) – The China-based e-commerce company beat estimates on both the top and bottom lines for the third quarter, as online orders remained strong even after coronavirus-related restrictions were lifted in China. Shares of JD.com slid about 2%.

Walmart (WMT) – Walmart resumed counting and monitoring the number of customers in its stores at any one time. The retail giant has had customer limits in place since April due to Covid, but had not been physically counting them in recent months. Separately, Walmart is selling its majority stake in Japanese supermarket chain Seiyu to KKR (KKR) and e-commerce company Rakuten for more than $1 billion. Walmart will keep 15% of Seiyu, with KKR holding 65% and Rakuten 20%. Walmart shares edged up 1% in the premarket.

Simon Property Group (SPG) – Simon will buy rival mall operator Taubman Centers (TCO) in a revised takeover deal worth $43 per share. That's down from an original deal worth $52.50 per share, struck in February before the full impact of Covid-19 on retailers took hold. Simon Property shares were up 7% in premarket trade.

PNC Financial (PNC) – PNC is buying the U.S. unit of Spanish banking company BBVA (BBVA) for $11.6 billion in cash. The deal is the second biggest US banking transaction since the 2008 financial crisis, trailing only last year's acquisition of SunTrust Banks by BB&T for $28.2 billion. The transaction represents an unwinding of BBVA's 2007 acquisition of Alabama-based Compass Bancshares. PNC shares rose 4%, while BBVA shares soared nearly 19% in premarket trading.

Caesars Entertainment (CZR) – British billionaire Fred Done, the largest stakeholder in British betting firm William Hill, will back the planned $3.7 billion takeover of the company by Caesars, according to a report in the Telegraph newspaper. Caesars shares rose more than 3% in the premarket.

Uber Technologies (UBER) – Uber is in talks to sell its autonomous driving unit to self-driving car startup Aurora, according to multiple reports. The talks are said to be ongoing with no certainty that a deal will be reached. Uber shares rose 3% in premarket trading.

Western Union (WU) – Western Union will suspend money transfers to Cuba, following a White House move to ban transfers that are sent through military-controlled companies like Western Union's main Cuban partner Fincimex. Western Union shares rose more than 1% in the premarket.

Qualcomm (QCOM) – The chipmaker received permission from the U.S. government to sell 4G mobile chips to China's Huawei, in an exception to an ongoing ban that took effect in September. Shares were little changed in the premarket.

Tapestry (TPR) – The company behind the Coach and Kate Spade luxury brands was upgraded to "overweight" from "neutral" at JPMorgan Chase. JPMorgan cited confidence in healthy earnings growth following a meeting with management, and sees the stock's current price as undervalued. Tapestry shares rose 6% in the premarket.

Activision Blizzard (ATVI), Take-Two Interactive (TTWO) – Evercore began coverage of both videogame makers with "outperform" ratings, citing a rich pipeline of games and growing user engagement by the industry. The companies' shares were nearly flat in the premarket.