Source

A lot of people are in love with their employer’s stock
Quote: “According to a 2004 survey by the Employee Benefits Research Institute, 13% of those employees surveyed, had over 80% of their 401(k) allocated in their own company’s stock!”

“Experts” recommend below 5-10 % of company stock
Quote: “Generally, it is said that you should have no more than 15% of your 401(k) invested in your own company. That’s the maximum, but most experts believe you should invest even less than that. (Most say 5-10%, or below is a good number.) Most professionally managed, defined-benefit pension plans only contain 2% of the employers stock.”