The decline in AMC Entertainment's stock price is a direct reaction to the company's Q4 financial results. Typically, financial results are a strong indicator of a company's performance, and negative or below-expectation results can lead to a decrease in stock price. Given that the article specifically mentions the stock trading lower post-results, it's clear that the market's immediate reaction was negative. This analysis assumes the financial results were not in line with market expectations, leading to a decrease in investor confidence and a subsequent drop in stock price.