It's a sign we're all extremely familiar with, but do you know where the "$" sign actually comes from?
That's the question being tackled this week in a fascinating new Mental Floss video, hosted by YouTube personality Craig Benzine.
According to Benzine, we don't actually know definitively where the sign comes from (go figure!), but there are a few popular theories.
One theory was apparently posited by American mathematician Florian Cajori in his 1928 book, History of Mathematical Notations. According to Cajori, the "$" sign had probably first started as an abbreviation for the Spanish Peso, and not the American dollar.
"Spanish Americans began abbreviating 'peso' in various ways in the 16th century," Benzine explains. "One popular abbreviation, 'P.S.,' evolved into the letters 'P' and 'S' getting kind of squished together into a new symbol."
There are several more theories, including Benzine's, which we won't spoil for you here. You have to watch. But what we do know for certain, he says, is that by the late 1700s the "$" symbol had started gaining in popularity, and became a standard way of denoting American dollars by the following century.
And the rest, as they say, is history.
For more on the origins of the "$," watch the Mental Floss video above.