The typical trade duration is days to weeks. Occasionally, one of the stock or mutual fund trades will have a duration of a few months, but these long term trends are not frequent in recent financial markets. Most of my institutional-investor clients are value in investors. They do not trade frequently. Forecasts are used as sell indicators.
Value investing involves a lot of analysis of the fundamentals prior to making a buy decision.
But often, a sell decision is not as rigorously generated when using fundamental analysis. When to buy. When NOT to sell. This is perhaps the most important thing that is helpful to a value investor. This is necessary in rapidly-changing financial markets.