Summary Summary Companies Amazon up as Jefferies sees easing costs Alibaba climbs as Ant Group's Jack Ma to cede control Macy's, Lululemon drop on holiday-quarter warnings Indexes up: Dow 0.39%, S&P 0.85%, Nasdaq 1.52% Jan 9 (Reuters) – The tech-heavy Nasdaq led gains among the main Wall Street indexes on Monday, boosted by shares of Amazon and Tesla, while signs of a cooling labor market supported bets of a slower pace of interest rate hikes by the Federal Reserve. Amazon.com Inc (AMZN.O) rose 3.4% after Jefferies said it saw cost pressures easing for the e-commerce giant in the second half…