• Stock market acronyms start with the stock market itself: stocks in the U.S. trade either on the NYSE (New York Stock Exchange) or the NASDAQ (National Association of Securities Dealers Automated Quotation), although NASDAQ insists that the full name is outdated and only the acronym should be used to describe the largest electronic exchange. Most stock market acronyms refer to specific segments of the market and are only used and understood by a small group of professionals, but some are widely used across the board by the investment community.
  
  

Market Indexes

• Stocks are grouped into several indexes depending on where they trade, their size, sector or other factors. The largest and most popular ones are NYSE (all stocks listed there); NASDAQ (all stocks that trade there); Dow Jones Industrial Average (DJIA), the 30 leading industrial stocks; and S&P 500 (Standard and Poor's 500 index), the 500 largest U.S. stocks by capitalization.
  
  

Products

• ADR (American depositary receipts) and ADS (American depository shares) represent shares of foreign companies listed on the NYSE. CEF (closed-end funds) and ETF (exchange-traded funds) are funds that invest in stocks or bonds and trade like a stock on the NYSE. CMO (collateralized mortgage obligations) are bonds backed by mortgages, while GNMA (Government National Mortgage Association) is a government-sponsored entity that packages mortgages into securities under the same name (GNMA bonds).
  
  

Research

• Many acronyms come from stock and bond research. GAAP (Generally Accepted Accounting Principles) is the U.S. accounting and reporting standard. The items that are most often scrutinized in a company's quarterly earnings report are EBITDA (earnings before interest, taxes, depreciation and amortization); R&D (research and development expenses); and EPS (earnings per share). Some of the most widely used ratios to evaluate stocks are P/E (price-to-earnings), P/S (price-to-sales), and PEG (P/E to EPS growth rate). Most comparisons and data are either YOY (year-over-year) or YTD (year-to-date). YTM (yield-to-maturity) is often used to evaluate bonds.
  
  

Orders

• GTC (good-till-cancelled) is a conditional order to buy or sell that stays on the books until cancelled; AON (all-or-none) is an order that must be executed in its entirety or not at all.
  
  

Popular

• Some abbreviations are not "official" but are often used by investors: PPS (price per share); the Qs (an abbreviation of an abbreviation: QQQQ is the trading symbol for an ETF that trades NASDAQ's 100 largest stocks); BB or OB (bulletin board stocks), lower-quality speculative stocks with minimal listing requirements); DRIP (dividend reinvestment plan), a popular program of reinvesting dividends free of charge); SIPC (Securities Investor Protection Corporation), a government entity that insures brokerage accounts against certain non-market related losses.