Benzinga has examined the prospects for many investor favorite stocks over the past week. Both bullish and bearish calls in coronavirus vaccine contenders were seen this week.Social media platforms were represented in both categories as well.September has a reputation as a harsh month for the markets, and it certainly has lived up to that reputation this year: volatility continued last week for various reasons. The Dow Jones industrials and S&P 500 ended the week essentially flat, with the Nasdaq only a little better, but all three indexes are down more than 4% since the start of the month, with the Nasdaq retreating about 8%.It was also a week in which the race for a COVID-19 vaccine continued, and the world's leading electric carmaker held its annual event – which failed to help the stock much.As usual, Benzinga continues to examine the prospects for many of the stocks most popular with investors. Here are a few of this past week's most bullish and bearish posts that are worth another look.Bulls Shanthi Rexaline's "Moderna Will Start To Outrun Coronavirus Competition In 2021, Analyst Says" details an analyst's take on why investors should buy the dip in Moderna Inc (NASDAQ: MRNA) shares."5 Reasons Pivotal Upgrades Twitter To Buy" by Jayson Derrick discusses the many points of logic behind the featured analyst's new bullish stance on Twitter Inc (NYSE: TWTR) stock.In "Chevron Has 'Significant Strategic Advantage,' MKM Says In Bullish Initiation," Priya Nigam reveals why Chevron Corporation (NYSE: CVX) is expected to generate huge free cash flow next year.A new analyst has jumped in the bullish camp for DraftKings Inc (NASDAQ: DKNG), according to Chris Katje's "DraftKings Can Reach .3B Revenue By 2030: Macquarie."For additional bullish calls, also have a look at "Analyst: Here's Where The S&P 500 Could Be In 20 Years" and "10 US Oil Stocks To Buy At Cyclical Lows." Bears In Aditya Raghunath's "Not All FAANG Stocks Are Going To Be Winners, Munster Says," makes the case that this group is in for a "fracturing." See whether Apple Inc (NASDAQ: AAPL) is a "have" or a "have not."Jayson Derrick's "Billionaire Barry Diller Blasts TikTok-Oracle Deal, Kyle Bass Says Security Threat 'Grave'" shows why this media mogul considers the Oracle Corporation (NYSE: ORCL) effort to win TikTok "ludicrous."The prospects for AstraZeneca plc (NASDAQ: AZN) to be the a first mover have dimmed. So says "AstraZeneca Has Lost The Lead In Race For Coronavirus Vaccine, Says SVB Leerink" by Shanthi Rexaline."Coronavirus Travel Worries Are Turning This American Express Analyst Bearish" by Priya Nigam indicates that American Express Company (NYSE: AXP) has high exposure to airline and lodging spending.Be sure to check out "Tech Selloff Is Far From Over, Warns Morgan Stanley" and "How Will The Election Impact The Banking Industry?" for additional bearish calls.At the time of this writing, the author had no position in the mentioned equities.Keep up with all the latest breaking news and trading ideas by following Benzinga on Twitter.See more from Benzinga * Options Trades For This Crazy Market: Get Benzinga Options to Follow High-Conviction Trade Ideas * Barron's Picks And Pans: Ackman Picks, Albertsons, Nvidia And More * Notable Insider Buys of the Past Week: Nikola, Transdigm And More(C) 2020 Benzinga.com. Benzinga does not provide investment advice. All rights reserved.