“But remove yourself and the picture frame from the equation.

“The stock doesn’t know you own it – it existed before you bought it and it’ll exist afterwards.”

Mr Lane continued: “It won’t necessarily act in the way you want it to during exactly the parameters you give it, and you need to know that going in.”

When to hit the sell button

“Regardless of the returns, stick to the principles of looking at the business performance first.”

Rather than panicking over numbers and chart lines, Mr Lane suggested a focus on questions like the following to use strategy instead of chance in decision making:

Is there anything in there to make you want to sell up?

Is management misallocating capital?

Has growth come to a standstill?

Has the story you bought into played out?