$

An S-shape with one or, in some typefaces, two vertical lines crossing it completely. See for the usage with explicitly two lines.

$ appears to have evolved circa 1775 in the United States from a common abbreviation for pesos, also known as piastres or pieces of eight, a P/raised-S ligature P^S.^[1] It was used in the US before the adoption of the dollar in 1785.^[2]

The "computing" sense is the result of homophony between English cache and cash, dollars being a form of cash.

$

1. money
   • 1954, Donald's Diary (in English):

     Uncle Ray's Loans / We lend $$$

   1. various currencies called dollar
      • 1977, advertisement page in Uncanny X-Men, #106, page 8

        Fool all your friends. You'll get a Million^[sic] $$$ worth of laughs with these exact reproductions of old U. S. Gold Banknotes (1840).

   2. peso
   3. escudo
   4. pataca
   5. milreis
2. (computing) cache
   • 2010, CIS501 lecture notes‎^[3] (in English), University of Pennsylvania:

     How to provide additional D$ bandwidth?

$

1. A substitute for the letter S, used as a symbol of money or perceived greed in business practices.

   Micro$oft Window$

   • 1971 February 26, “Motor City: March Special” (advertisement), in The Daily Herald-Tribune, volume 58, number 168 (in English), Grande Prairie: Bowes Publishers Limited, After Hours, page 2:

     BE SAFE - BE SURE ¶ Come in NOW and $AVE

   • 1992, Michael Rumaker, To Kill a Cardinal (in English), [Rocky Mount, N.C.]: Arthur Mann Kaye, →ISBN, page 37:

     While shrilly blowing whistles and setting off marine fog horns, they began scattering queer—as in “queer-as-a-three-dollar-bill”—money, phony 100s, 50s and 10s created by the activist artists group Gran Fury, down onto the floor of The Exchange, the backs of the bills reading: FUCK YOUR PROFITEERING. PEOPLE ARE DYING WHILE YOU PLAY BUSINESS. AID$ NOW.

   • 1992 May 6, The Hamilton Spectator (in English), Hamilton, Ont., →ISSN, →OCLC, page C1, column 6:

     BEST BUY$

   • 2015, “Pixtopia”, in Star vs. the Forces of Evil, season 1, episode 6b (in English):

     [the text below is written on-screen in large letters, once Marco reveals his "emergency cash stash] Marco'$ emergency ca$h $ta$h

2. A substitute for the letter S, used as a censored or filter-avoidance spelling.

   $h!t ― shit

$

1. A currency sign for the dollar, peso, and pataca.
   • 2024 May 24, Susan Griffin, “How the super rich party at the Monaco Grand Prix”, in CNN‎^[4] (in English):

     Some bottles of champagne at Amber Lounge afterparties can cost €20,000 ($21,600).

   • 2025 June 13, Luciana Lopez and Chris Isidore, “US Steel and Nippon Steel say Trump has approved their partnership”, in CNN Business‎^[5] (in English):

     US Steel was once a symbol of American industrial power. It was the most valuable company in the world and, soon after its 1901 creation, became the first to be worth $1 billion.

2. An unofficial currency sign for the escudo.
3. (programming) Prefix indicating a variable in some languages, such as Perl, PHP, or shell scripts.

When used as a currency symbol, $ precedes the number it qualifies in English, despite being pronounced second. For example, "$1" is read as one dollar, not dollar one unlike the usage in languages such as French or German: "1 $", "2,50 $".

When used for the Portuguese escudo, $ is placed between the escudos and centavos, e.g. 2$50. The official symbol for the escudo is (with two bars), but that form is unified with the single-bar form in Unicode. A single-bar dollar sign is frequently employed in its place even for official purposes.