Through Berkshire Hathaway (NYSE: BRK.A), Warren Buffett has built a reputation for picking long-term stock market winners and building a portfolio that thrives in different economic phases.However, even his most trusted investments remain susceptible to short-term technical signals that suggest possible trouble ahead.Now, Coca-Cola (NYSE: KO), one of Buffett’s favored stocks, accounting for 8.4% of his portfolio, has formed a ‘death cross‘ for the first time since July 2023 – a bearish signal when the 50-d ...