On selling a stock:
"Usually I sell a stock on one of three occasions. First, I sell a security if I make a mistake. The second occasion when to sell is when you find something that's better. By better I mean a better risk and return combination. You do that by constantly improving your portfolio's opportunity cost. And the third occasion when to sell is when the valuation swings way too much to the extreme high, or when the market price deviates too much from the intrinsic value. When this happens your opportunity cost becomes cash. Essentially it's all about opportunity cost. But it's not that easy because everyone's opportunity cost is different and everyone's understanding of opportunity cost is different."
On value investing in today's market:
I've been in the market for 26 or 27 years. What I've observed is that authentic value investors have always been the minority. But today, at least in China, I see more and more investors call themselves value investors. But they may not understand the essence of value investing. As Ben Graham said, in the short term the stock market is a voting machine and in the long term it's a weighing machine. If you are a true value investor, you shouldn't care about the voting results because ultimately intrinsic value is determined by the long term profitability and growth. It has nothing to do with how market participants vote.
What to focus on when analyzing a business:
So if you are interested in a business, you'll find out that you should focus on the long term competitive advantages of this business. What would the business look like in 10 years or longer? Can it sustain its competitive advantages in 10 years? Can it sustainably grow? Will it continuously earn a high return on capital?
The full interview is here https://www.gurufocus.com/news/1232294