The shares of AstraZeneca plc (NASDAQ:AZN) have seen a lot of movement lately, with the drugmaker's Covid-19 vaccine popping up in the news almost daily. Once again, the security is making headlines today, after announcing that previous claims that its vaccine was 79% effective against protecting patients from coronavirus symptoms during its phase three trial were incorrect, and that the vaccine actually has a 76% efficacy rate. The security is attempting to brush off this gaff, and was last seen up 0.3% to trade at $48.89.

As we mentioned, it's been bumpy road for AZN during the past year. While Monday's news allowed the equity to briefly top its 80-day moving average -- a trendline that's more or less kept a lid on shares since last September -- the takeover was brief, and now the equity is struggling just below its year-to-date breakeven, though it still sports a year-over-year lead of around 21%. 

Amid all the chaos, short sellers have been piling on AZN, with short interest up 30.9% in the last two reporting periods. There's still plenty of room on this bearish bandwagon, however, as the 86.28 million shares sold short make up just 3.3% of AZN's available float. 

Darden Restaurants Inc. (NYSE:DRI -- $133.93) owns and operates full-service restaurants in the United States and Canada. Darden Restaurants will report its Q3 earnings of 2021 before the bell today.

Momo Inc. (NASDAQ:MOMO -- $14.54) operates a mobile-based social and entertainment platform in the People's Republic of China. Momo will report its Q4 earnings of 2020 before the bell today.

GAN Ltd. (NASDAQ:GAN -- $23.05) operates as a business-to-business supplier of internet gambling software-as-a-service solutions to online casino gaming and online sports betting applications in the United States. GAN will report its Q4 earnings of 2020 after the close today.

Oxford Industries Inc. (NYSE:OXM -- $80.65) designs, sources, markets, and distributes products of company owned and licensed brands, and private label apparel products. Oxford Industries will report its Q4 earnings of 2020 after the close today.

Progress Software Corp. (NASDAQ:PRGS -- $41.82) develops business applications. Progress Software will report its Q1 earnings of 2021 after the close today.

Science Applications International Corp. (NYSE:SAIC -- $94.83) provides technical, engineering, and enterprise information technology (IT) services primarily in the United States. Science Applications will report its Q4 earnings of 2020 after the close today.

Here is a quick recap of how yesterday's earnings announcements compared to expectations:

General Mills Inc. (NYSE:GIS -- $61.19) engages in the manufacture and marketing of branded consumer foods sold through retail stores. Earnings per share were up 6.49% year over year to $0.82, which missed the estimate of $0.84. Revenue of $4,520,000,000 higher by 8.13% from the same period last year, which beat the estimate of $4,450,000,000.

Winnebago Industries Inc. (NYSE:WGO -- $77.15) manufactures and sells recreation vehicles and marine products primarily for use in leisure travel and outdoor recreation activities. Earnings per share rose 216.42% over the past year to $2.12, which beat the estimate of $1.41. Revenue of $839,886,000 higher by 33.99% from the same period last year, which beat the estimate of $805,230,000.

Worthington Industries Inc. (NYSE:WOR -- $64.17) operates as a metals manufacturing company. Earnings per share rose 112.50% year over year to $1.36, which beat the estimate of $1.25. Revenue of $759,109,000 decreased by 0.64% from the same period last year, which missed the estimate of $872,500,000.

H.B. Fuller Co. (NYSE:FUL -- $58.18) formulates, manufactures, and markets adhesives, sealants, coatings, polymers, tapes, encapsulants, additives, and other specialty chemical products. Earnings per share increased 94.12% over the past year to $0.66, which beat the estimate of $0.47. Revenue of $725,904,000 higher by 12.27% from the same period last year, which beat the estimate of $680,100,000.

KB Home (NYSE:KBH -- $43.36) operates as a homebuilding company in the United States. Earnings per share rose 61.90% year over year to $1.02, which beat the estimate of $0.92. Revenue of $1,142,000,000 up by 6.13% year over year, which missed the estimate of $1,210,000,000.

Shoe Carnival Inc. (NASDAQ:SCVL -- $54.44) operates as a family footwear retailer in the United States. Earnings per share increased 116.67% year over year to $0.52, which beat the estimate of $0.51. Revenue of $253,897,000 up by 5.85% from the same period last year, which missed the estimate of $253,900,000.

Looking ahead to tomorrow, an onslaught of economic data is due out on Friday, including reports on personal income, consumer spending, core inflation, trade in goods and the consumer sentiment index. All economic dates listed here are tentative and subject to change.

Burger King parent Restaurant Brands International Inc (NYSE:QSR) has been in rally mode since its last earnings report in mid-February -- breaching the $56-58 region, which was home to major lows back in 2016 and 2018, as well as the $59 level, which is a 61.8% Fibonacci retracement of the stock's 2018 peak through its 2020 trough. 

And while short interest makes up just 2.8% of QSR's float, it would take almost a week for bears to cover their positions, which could lead to a potential short squeeze situation. The security could benefit from a round of analyst upgrades and/or price-target hikes, too. Of the 17 in coverage, seven still call the fast food stock a "hold," while the 12-month consensus price target of $66.92 is a slim 2.9% premium to Friday's close.

This looks like an excellent time to get in on QSR's next move with options too. The security's Schaeffer's Volatility Index (SVI) of 27% stands in the lowest percentile of its annual range, implying options traders are pricing in extremely low volatility expectations for the equity at the moment. We should also note that our recommended call option has a leverage ratio of 7.9 and will double in a 12.4% rise in the underlying equity.

Subscribers to Schaeffer's Weekend Trader options recommendation service received this QSR commentary on Sunday night, along with a detailed options trade recommendation -- including complete entry and exit parameters. Learn more about why Weekend Trader is one of our most popular options trading services.