Hyper-inflation has resulted from time to time, most notably during World War II, and most recently in Zimbabwe. The world went crazy after Zimbabwe’s annual inflation rate hit an estimated 2.31 x 10^8 percent, or 40-50 million percent per month. However, inflation rates have been billions of times worse (in the case of post-WWII Hungary).
Greece:
During its occupation by Nazi Germany in 1941-1944, the rate of inflation hit 8.55 x 10^9 percent per month (prices doubled every 28 hours). As a result, the 100 Milliard, or 100 Billion Drachmai note was issued in November 1944. Although this note only displays 2 zeroes, it still contained a hefty denomination.
Yugoslavia:
Yugoslavia’s rate of inflation hit 5 x 10^15 percent inflation between 1 October 1993 and 24 January 1994 (prices doubled every 16 hours). The rate maxed out at 323 million percent per month. A 500 Billion Dinar note was issued in December 1993, and was worth roughly $6 US at the start of the day. By evening, it was only worth an equivalent $3 US.
Zimbabwe:
In 2008, a 100 billion dollar bank note was issued in July. In January 2009, however, a 100 Trillion Dollar note was released, making it the the bank note with the most zeroes (14). Only two weeks later the government dropped 12 zeroes from the curency, making the note worth Z$100. Tricky.
Hungary (29 zeroes!):
The most severe known incident of inflation was in Hungary after the end of World War II, peaking at 4.19 × 1016 percent per month (prices doubled every 15 hours). In order to keep up with the inflation rate, the government issued the 100 Million B-Pengo note in 1946. (A larger denomination note was created but never issued). A B-Pengo is equal to one billion pengo, but in European terms a billion is equal to one-thousand milliard, or one trillion in American terms. Therefore, the 100 Million B-Pengo is essentially equal to 100,000,000,000,000,000,000 (100 quintillion) Pengo. It was worth about U.S. $0.20 in 1946. Eventually, 29 zeroes were dropped when the Forint was adopted in mid-1946.
