Here are the biggest calls on Wall Street on Thursday: Wells Fargo initiates Amazon as outperform Wells said in its initiation of Amazon that the firm sees a margin inflection sooner than investors realize. "Top pick AMZN on North American Retail margins inflecting ahead of expectations, reaching 2019 levels in 2025, one year ahead of Street expectations." Read more about this call here. Jefferies downgrades Las Vegas Sands and Wynn to hold from buy Jefferies downgraded several casino stocks, mainly on valuation. "We are downgrading WYNN, LVS to Hold from Buy because we believe the upside/downside is more balanced than...