The bit as a unit of money is worth 1/8 of a United States dollar.

The term comes from the colonial times when the United States did not have its own money, and in circulation were coins made of real silver or gold, which were of significant value. Therefore, to make change money, these coins were cut into eight radial slices, just like pizza is cut today. These slices were naturally called "bits," and the whole dollar coin "pieces of eight."

Since the bit doesn't directly correspond to any of regular modern U.S. coins, later bits were usually counted in twos: two bits (a quarter, i.e., 25 cents), four bits, six bits...

Because there was no one-bit coin, a dime (10c) was sometimes called a short bit and 15c a long bit.

Gimme six bits' worth o'ticket

On a train that runs somewhere...

(Langston Hughes, Six-Bits Blues)

The New York Stock Exchange continued to list stock prices in eighths of a dollar until June 24, 1997, at which time it started listing in sixteenths. It did not fully implement decimal listing until January 29, 2001, according to the research staff at the NYSE.

Danish West Indies 20 bit stamp, 1905

From 1905 to 1917, the Danish West Indies used stamps denominated in bits and francs with 100 bits to the franc; the lowest value was 5 bits.