Dash Dash The dash is a punctuation mark that is similar in appearance to and , but differs from these symbols in both length and height. The most common versions of the dash are the en dash (–), equal to half the height of the font; the em dash (—), twice as long as the en dash; and the horizontal bar (―), whose length varies across typefaces. Historically, the names of en dash and em dash were loosely related to the width of a lower-case "n" and upper-case "M", respectively, in commonly used typefaces. Usage varies both within English and in
Uptick rule on 2009-04-08. A modified form of the rule was adopted on 2010-02-24. In 1938, the U.S. Securities and Exchange Commission (SEC) adopted the uptick rule, more formally known as "rule 10a-1", after conducting an inquiry into the effects of concentrated short selling during the market break of 1937. The original rule was implemented when Joseph P. Kennedy, Sr. was SEC commissioner. In 1994, the NASD and Nasdaq adopted their own short sale price tests, known as NASD Rule 3350, based on the last bid rather than on the last reported sale. In 1978, the purpose of the uptick rule was