Peter Lynch Won't Hold Your Hand

Different investors will prefer different strategies and implementation options based on risk tolerances, capacity to implement illiquid investments, ability to access the top managers, and available resources for managing a complex portfolio. The traditional portfolio shown in Exhibit 4 is a fairly typical structure designed to capture diversified beta through long-only managers—it is focused solely on public equity exposure, and although it allocates 20% of its total to both a regional and small-cap manager, the objective is clearly to capture emerging markets beta.
—Mary Jo Palermo, Eric Winig, Greg Moessing: Highlights from The Case for Diversified Emerging Markets Exposure, Cambridge Associates, 2011.

Diworsification: The term was coined by the legendary investor Peter Lynch in his book, One Up on Wall Street, where he suggested that a business that diversifies too widely risks destroying their original business because management time, energy and resources are diverted from the original investment.
—Investopedia