Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

How to evaluate stocks? e.g. Whether some stock is cheap or expensive?
I look at the following ratios and how these ratios developed over time, for instance how did valuation come down in a recession, what was the trough multiple during the Lehman crisis in 2008, how did a recession or good economy affect profitability of the company. Valuation metrics: Enterprise value / EBIT (EBIT = operating income) Enterprise value / sales (for fast growing companies as their operating profit is expected to be realized later in time) and P/E Profitability: Operating margin, which is EBIT / sales Cashflow / sales Business model stability and news flow