How sector stock funds can make your portfolio whole By: MarketWatch April 07, 2014 at 07:01 AM EDT Sector funds can be rewarding investments. But if you use them, you need to understand exactly what you’re buying, writes Jonathan Burton. Read More >> Related Stocks: HEALTHCARE Healthcare Alphadex FT ETF Healthcare ETF Vanguard Johnson & Johnson Merck & Co Nasdaq Biotechnology Ishares ETF Pfizer Standard & Poors 500