Collectible currency has long held interest and value around the world. The history of coin collecting dates back hundreds of years, and some coins on the market today are worth millions. This is an intriguing hobby that many people enjoy. Learn more about coin collecting and what makes coins collectible.
When and Where Did Coin Collecting Start?
Coins were first minted around 650 B.C. At that time, the only purpose for collecting them was to amass wealth. By the Roman era, however, there were some indicators that coins were being seen as valuable collectibles. 
Caesar Augustus, who ruled Rome from 27 B.C. to 14 A.D., is commonly cited as a coin collector. He’s known to have kept a great number of coins and given these as gifts. Around the 14th century, coin collecting gained traction as a hobby, though it was only enjoyed by the rich. Coin collecting was in fact called the ‘hobby of kings,’ and early collectors included:
- Petrarch (1304-1374) 
- Pope Boniface VIII (1235 – 1303) 
- Louis XIV (1643 – 1715) 
- Henry IV (1553 – 1610) 
- Elector Joachim II (1505 – 1571) 
Through the 16th century, coins were collected for their distinctive designs. These pieces were seen much like art. Around the 17th and 18th centuries, collectors began to consider the historic value of coins as well. Numismatics emerged as an academic discipline focused on the study of coins, and coin collecting gained popularity among the middle class, though it was still seen as a sign of wealth.
In the 19th century, coin collecting expanded to become an international hobby. People began studying coins from other countries and amassing collections of coins from around the world. The Numismatic Society of London, known today as the Royal Numismatic Society, was founded in 1836.  The American Numismatic Society began in 1858,  and the American Numismatic Association followed in 1891. 
Federal coinage reforms in the United States and the gold rush in California led to new developments in collectible U.S. currency through the mid-1800s. By the 20th century, the American Numismatic Society was well-established as one of the leading numismatic research institutions in the world. The society started its graduate seminar in numismatics in 1952 and began holding the annual ‘Coinage of the Americas Conference’ in 1984. 
Coin collecting has continued to gain popularity around the world and is now a common hobby that’s easily accessible. Modern collectors can get started with a minimal investment, and they have access to numerous resources that explore the history and value of specific coins.
How Popular Is Coin Collecting Today?
Coin collecting as a hobby has enjoyed steady popularity for many decades. Though it’s difficult to pinpoint the number of coin collectors in the United States or around the world, there are several statistics that support the prominence of coin collecting as a hobby:
- Globally, the coin collecting market has about $17.59 billion in annual revenue. 
- The number of coin collectors in the U.S. has increased 1.89% annually since 2000. 
- There are at least 10 coin companies in the U.S. with annual sales exceeding $100,000,000. 
- There are at least 5,000 active coin companies in the US. 
- In 2019, six U.S. coins sold for more than $1 million each. 
- The NGC coin collecting app has over 10,000 installs from Google Play alone. 
What Makes Certain Currencies Collectible and Not Others?
The value of certain types of collectible currency and collectible money notes is based upon:
- Rarity: Among the most important factors in a coin’s collectibility, rarity determines how many coins were struck in a particular mintage. The fewer coins exist, the more valuable each one is. Condition matters as well. Though there may be several of a certain coin available, if most are scratched or damaged, the high-quality coins become increasingly valuable.
- Date: The date that a coin was produced can impact its value as a collectible. However, it’s important to note that older coins are not always worth more. Other factors are typically more important.
- Mint mark: The mint mark specifies where a coin was struck. In some cases, only a small number of coins were produced at a particular mint, making that mint mark a critical factor in the coin’s collectibility.
- Condition: Coins are graded on a scale of 1 to 70 by professional graders. The coin’s grade determines its value to a large extent. It’s important to keep in mind, however, that certain aspects of the grade, like ‘eye appeal,’ are subjective to a certain degree. 
- Mint errors: When a mint makes an error in striking a coin, that coin becomes very collectible because of the intrigue and rarity of that element.
Consider some of the most collectable coins on the market, and you’ll see how these factors can impact the demand for a coin and the interest that it receives from collectors.
The 1969-S Lincoln Cent with a Double-Die Obverse is worth at least $30,000. The design on this coin is bordered by a crooked copy of the original image. When the error was discovered, the Secret Service confiscated most of the coins, increasing the value of those that remain. 
The 1933 Saint-Gaudens Double Eagle 20 Dollar coin is one of the rarest in existence. Only 11 instances of this coin remain, 10 of which are in the possession of the U.S. government.  King Farouk of Egypt sold this coin in 2002 for $7.5 million. 
What Common Features Do Currency Collectors Look For in Currencies They Collect?
When you’re evaluating collectable currency for sale, consider: 
While some collectible U.S. currency is worth tens or hundreds of thousands, there are also interesting pieces you can find in your pocket change, and affordable uncirculated currency that you can purchase for your collection. Nearly anyone can get involved in this hobby, regardless of the amount they want to invest.
- Coin Spot. The History of Coin Collecting, http://www.coinspot.org/history.html. Accessed October 2, 2020.
- Britannica. Petrarch, https://www.britannica.com/biography/Petrarch. Accessed October 2, 2020.
- Britannica. Boniface VIII, https://www.britannica.com/biography/Boniface-VIII. Accessed October 2, 2020.
- Britannica. Louis XIV, https://www.britannica.com/biography/Louis-XIV-king-of-France. Accessed October 2, 2020.
- Britannica. Henry IV, https://www.britannica.com/biography/Henry-IV-king-of-France. Accessed October 2, 2020.
- Britannica. Joachim II Hektor, https://www.britannica.com/biography/Joachim-II-Hektor. Accessed October 2, 2020.
- The Royal Numismatic Society. Home, https://numismatics.org.uk/. Accessed October 2, 2020.
- American Numismatic Society. History of the American Numismatic Society, http://numismatics.org/about/history/. Accessed October 2, 2020.
- Mhojhos Research. Coin Collecting Market Analysis, https://mhojhosresearch.com/2020/05/06/coin-collecting-market-analysis-global-and-europe/. Accessed October 2, 2020.
- CoinWeek. href=”https://coinweek.com/education/coin-collecting-large-rare-coin-market/” target=”_blank” rel=”noopener noreferrer”>Coin Collecting: How Large is the Rare Coin Market? https://coinweek.com/education/coin-collecting-large-rare-coin-market/. Accessed October 2, 2020.
- Numismatic News. Year in Review: Collector Market Stable, https://www.numismaticnews.net/article/year-in-review-collector-market-stable. Accessed October 2, 2020.
- American Numismatic Association. American Numismatic Association, https://www.money.org/ana-history. Accessed October 2, 2020.
- Google Play. NCG, https://play.google.com/store/apps/details?id=com.ngccoin.ngcmobile&hl=en. Accessed October 2, 2020.
- Komo News. Mistakes That Pay Big: Valuable Error Coins, https://komonews.com/sponsored/sell-gold/mistakes-that-pay-big-valuable-error-coins. Accessed October 2, 2020.
- Coin Trackers. What Makes a Coin Valuable? http://cointrackers.com/blog/38/what-makes-a-coin-valuable/. Accessed October 2, 2020.
- ABC News. Judge Says 10 Rare Gold Coins Worth $80 Million Belong to Uncle Sam, https://abcnews.go.com/Business/judge-10-rare-gold-coins-worth-80-million/story?id=17159793. Accessed October 2, 2020.
- Federal Trade Commission. Investing in Collectible Coins, https://www.consumer.ftc.gov/articles/0136-investing-collectible-coins. Accessed October 2, 2020.