Investing Fundas Revisited

I was just reading this article at seekingalpha website and found

Peter Lynch, former manager of the Fidelity Magellan Fund says in this article :
You’re already highly exposed to your job - after all, it’s your job that pays your salary and probably your retirement contributions and health insurance. The last thing you want to do is to increase your financial exposure to the industry you work in or its suppliers or customers.

I saw this clearly in my job as a research analyst covering the communications equipment sector during the boom and bust of 1998 to 2002. Many of my industry contacts were intelligent and sophisticated people who saw that demand for their firms' products was strong, and in some cases realized that their own company (or a competitor) was gaining market share. So they mistakenly bought stocks in their own sector. When the market for communications equipment subsequently collapsed to the surprise of most people in the industry, many of them lost not only their jobs, retirement contributions, health insurance and other benefits, but also took a severe hit to their investment portfolios.

So in theory, instead of buying stocks based on your work knowledge, what you actually want to do is to hedge your exposure to the industry you work in.

This echoes with what I wrote earlier.