You can invest to either maximize profits (by concentrating, my current strategy) or preserve your wealth (by diversifying).

A well-diversified portfolio should include exposure to all 10 major sectors of the economy:

• Oil & Gas - Oil & Gas Producers; Oil Equipment, Services & Distribution
• Basic Materials - Chemicals, Basic Resources (Forestry & Paper, Industrial Metals, Mining)
• Industrials - Construction & Materials; Industrial Goods & Services
• Consumer Goods - Automobiles & Parts; Food & Beverage; Personal & Household Goods (Household Goods, Leisure Goods, Personal Goods, Tobacco)
• Health Care - Health Care Equipment & Services; Pharmaceuticals & Biotechnology
• Consumer Services - Retail; Media; Travel & Leisure
• Telecommunications - fixed and mobile
• Utilities - Electricity; Gas, Water & Multiutilities
• Financials - Banks; Insurance; Financial Services
• Technology - Software & Computer Services; Technology Hardware & Equipment