Oophorectomy is the surgical removal of the ovaries of a female animal. In the case of non-human animals, this is also called spaying. It is a form of sterilization.
The removal of the ovaries together with the Fallopian tubes is called salpingo-oophorectomy. Oophorectomy and salpingo-oophorectomy are not common forms of birth control in humans; more usual is tubal ligation, in which the Fallopian tubes are blocked but the ovaries remain intact.
In humans, oophorectomy is most usually performed together with a hysterectomy - the removal of the uterus. Its use in a hysterectomy when there are no other health problems is somewhat controversial.
In animals, spaying involves an invasive removal of the ovaries, but rarely has major complications; the superstition that it causes weight gain is not based on fact. Spaying is especially important for certain animals that require the ovum to be released at a certain interval (called estrus or "heat"), such as cats and dogs. If the cell is not released during these animal's heat, it can cause severe medical problems that can be averted by spaying or partnering the animal with a male.
Oophorectomy is sometimes referred to as castration, but that term is most often used to mean the removal of a male animal's testicles.
A stock symbol or ticker symbol is a shorthand code used to uniquely identify shares of a publicly-traded corporation on a particular stock market.
A stock symbol may either be comprised of letters, numbers or a combination of both.
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In the United States, modern letter-only ticker symbols were developed by Standard and Poor's (S&P) to bring a national standard to investing. Previously, a single company could have many different ticker symbols as they varied between the dozens of individual stock markets. The term ticker refers to the noise made by the ticker tape machines once widely used by stock exchanges.
The S&P system was later standardized by the securities industry and modified as years passed.
| # of Letters | Exchange |
| 1 | NYSE |
| 2 | NYSE |
| 3 | NYSE or AMEX |
| 4 | Nasdaq |
| 5 or more | (special) |
Currently a glance at a U.S. stock symbol and its appended codes can tell an investor where a stock trades and may give insight to the company's performance.
For most stock symbols, the letters are simple identifiers. One- or two-letter symbols always trade on the New York Stock Exchange (NYSE), three letter codes may trade on either the NYSE or American Stock Exchange (AMEX), Four- and five-letter codes trade on the Nasdaq, although five-letter ticker symbols are usually a special class of stock. For example, the ticker symbols of mutual funds must be five letters long and end in "X".
Sometimes the stock symbol has become more recognizable than a company's real name. For instance, more people knew the Minnesota Mining and Manufacturing Company by the way its three-letter ticker ("MMM") is pronounced on Wall Street, "3M," leading to an official name change in 2002. Likewise, International Business Machines officially changed its corporate name to "IBM" to match its ticker symbol.
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