By contrast, two Ninety One portfolio managers – one a deep value and the other a quality investor – have spent the past two decades holding their investment philosophy and process constant, even as it cost them periods of relative underperformance. And, in an unexpected twist, their two vastly different investment disciplines have led them to some similar stocks.

When to sell?

While you should not alter your investment strategy or its execution unless it was incorrect at the outset, or your personal or financial circumstances change, we have previously identified several warning signals that should trigger the re-evaluation of your investment strategy.

A key trigger we identified was “Evidence of investment philosophy drift.”…