In British slang, a "pony" is a term used to describe £25 (or sometimes $25) in currency. The word has been traced back to the late 18th century in London, and its etymology has been suggested to come from various sources. Some believe that in the 18th century, £25 was the typical price paid for a small horse, while others suggest that an Indian twenty-five rupee banknote featured a pony, and this image was also connected to the cash amount. A final claim is that "pony" might derive from the Latin words ‘legem pone’, which means ‘payment of money, cash down’ which begins on the March 25, a quarter day in the old financial calendar, when payments and debts came due.
In Cockney rhyming slang, "pony" is also used to refer to £25. Other Cockney rhyming slang terms for money include "monkey" for £500, "score" for £20, "bullseye" for £50, "ton" for £100, "deep sea diver" for £5, "Lady Godiva" for £5, "Ayrton Senna" for £10, "cock and hen" or "cockle" for £10, "nicker", "nugget", or "Alan Whicker" for £1.
In the world of banking and investments, "pony" is also a slang term used to describe £25 (or sometimes $25) in currency.
