In a word… “Demand!” Supply and demand moves all markets, and in the rare coin market, demand drives return on investment. A coin’s population drives supply, and when supplies are high, prices are usually lower when the coin is more readily available.

However, when a coin is scarce and difficult to obtain, it is usually in high demand because of collectors who need that specific coin to finish a collection, which can create the potential for profit appreciation for key date coins.

It makes sense that rare U.S. coins have a limited and fixed supply because they aren’t minted anymore, and because of that, these coins also enjoy an ever-increasing demand because they are not easily obtainable. Relatively small increases in demand tend to push prices upward, with the rarest coins generally appreciating the most over time.

Demand For Key Dates Create A High Potential For Profit Appreciation


“Key dates and rarities should remain a focus for all high end rare coin investors. Because they are seldom seen in the market, those coins which are a key to finishing a set have tremendous appeal for collectors, regardless of their quality. Demand is always strong and, therefore, price sustainability and upward price pressure is present even when the overall market is soft.”


Ever since U.S. coin collecting became a hobby, most coin enthusiasts have sought to complete, or nearly complete, a set of a particular type of U.S. coins. The scarcest and most desired coins in sets are the “Key Dates,” some which have become legendary.

“Key date” coins are coins in each series that are usually the most valuable, often the rarest and hardest to find. They tend to have higher price appreciation than their common-date counterparts.

Key date coins, or “Keys,” are what many collectors need to complete a collection and are usually the last to be purchased by novice collectors. Some savvy collectors buy the key dates first when starting a collection so they’re not blocked from finishing a collection due to a missing key date. “Blocker” coins are those hard-to-find key dates that some people purchase as an investment, for when collectors are willing pay inflated prices for a coin just to finish a collection.

Key date coins are considered the “Blue Chips” of rare coins because collectors want and need them, increasing key date value. The impressive higher grade “choice” key date examples are even more desired and more valuable than lower grade key dates.

After the “Keys,” the next level of difficult-to-obtain coins in a series are often referred to as “Semi-Key Dates” or simply “Semi-Keys” which have higher value than common dates.

Most U.S. coin collectors know the 1909-S V.D.B. Lincoln Cent as one of the most popular key date coins


What makes a coin a “Key” is somewhat complicated because there are many date issues that are easy to obtain in lower grades, yet very hard to find in higher grades.

Collectors who want a series in near-uncirculated condition may find that some date/mint combinations are extremely rare and hard to locate.

This is because these originally low mintage coins were frequently kept first by collectors and saw little or no circulation, while common date coins were rarely saved and typically became heavily worn over time.


Since the foundational “Key Date” coins in a set are often what prevents the collection from becoming a complete set, it makes sense that experienced collectors often choose to begin a collection by first obtaining specimens of the key dates in the series. Once the key dates are obtained, then completing the set is just a matter of “filling in the blanks” of the missing coins.

The pursuit of key date coins is an important part of coin collecting and a rite of passage for every set collector. The building of a set requires a defined set of objectives, and generates a growing feeling of satisfaction, as the collection progresses to completion. Collectors are generally willing to pay a higher price for the key dates simply because they need them to complete their sets.

When it comes to the overall value of a completed set, it is the key date coins that often represent a major share of the collection’s value. This is because the key date rarity commands attention and drives competitive bidding at auctions when these coins are offered.



A very common question for both coin collectors and investors is, “What coins should I buy?” All U.S. coinage series have certain dates that are difficult to obtain. For example:

  • Low mintages or short run varieties
  • Low survival rate in higher grades
  • Mass meltings with low survivors
  • Condition rarities, like poor strikings
  • Mint errors, like double dies
  • Uncirculated coins in higher grades
  • Popular series/date that become scarce

Coin population can influence a coin’s value, but low survival rates tend to elevate prices more than just the mintage quantity.


Each series has key dates, and there are too many key dates to mention here. A few of the most collectable key date coins are in the Type I $20 gold, $10 Indian and Morgan silver dollar series. Here are a few “Key” examples:

THE 1861-S $20 “PAQUET”

Anthony C. Paquet was an assistant U.S. Mint engraver whose intricate coin designs are recognized today as fine artwork.

Paquet’s new design for $20 Coronet Liberty Double Eagles was both approved and rejected at the Philadelphia Mint in the year 1861, and only two of the “P–mint” Paquet $20s are known to exist to this day. The crowning achievement of any numismatist would be to own one of these two examples.

In 1861, the San Francisco Mint was a bit slower to receive news that the Paquet design would not be used. A telegraph message was sent to the San Francisco mint ordering a return to the old style Longacre reverse. This message appears to have taken a considerable amount of time to reach the mint and by the time it had, the mint had already minted 19,250 coins, worth $385,000, and released them into general circulation.

The 1861-S Paquet key date is the rarest Liberty Head Double Eagle produced by the San Francisco Mint. And it would be a crowning achievement to add one of these coins to any collection.


The Rolled Edge was the first regular production Eagle of the new design by noted American sculptor Augustus Saint-Gaudens.

Mint records and correspondence indicate that 31,500 examples were struck; however, nearly all of these were melted because of minting issues with the design. The Chief Engraver of the United States Mint, Charles Barber, modified Augustus Saint-Gaudens’ original design by creating a thicker, raised rim.

The exact number of survivors is not known with certainty. The surviving examples are mostly high quality and were either saved as assay pieces or obtained directly from the mint prior to the decision to melt the issue. It is thought that just 50 of the 1907 Rolled Edge Eagles were preserved for museums, numismatists and those associated with the design.

It is estimated that 35-45 specimens have survived in mint state grades. These coins now represent the absolute key date in a set of circulation strike Indian Eagles and would be a prize coin for any collector.


The Carson City Mint, born as a result of the discovery of the Comstock Lode, had been closed for four years prior to 1889. It did not reopen until the third quarter of that year. In October 1889, the Carson City Mint got ready to produce its next quantity of Morgan silver dollars.

Because the mint had been closed, crews had to clean the offices and machinery before production could begin. As a result, the mint only produced 350,000 coins in 1889, and all of these coins came out in the last three months of the year.

The 1889-CC Morgan dollar was one of the lower mintage issues of the entire series. Many other less-famous dates had lower mintages, but many 1889-CC silver dollars met an early demise. For unknown reasons, approximately 250,000 to 325,000 1889-CC silver dollars were eventually melted, securing this date as one of the keys to a set of Morgan dollars.


A sound purchasing philosophy is to buy the rarest, most desirable coins in a specific series, in the highest grade possible within a budget. Practicing this purchasing pattern should do very well over time. Key date coins in nearly all series have performed brilliantly during past decades and have consistently outperformed their common-date counterpart coins.

Prices of extremely rare coins have historically outpaced those of other rare coins, because this is one of the thinnest markets in all of hard assets. Although key date coins can be more expensive than common date rare coins, their excellent historical performance more than justifies the higher purchase price for many forward-thinking investors.


It’s good advice to purchase coins that are always in high demand. When it comes time to sell, that key date is very likely a missing coin in someone’s collection. A missing key date in a collection is called a “blocker” coin, which is needed to complete a collection. When these key date coins are made available, they are usually purchased quickly. Select key date coins inspire competition and strong prices, whenever they are offered for sale.

Every collector knows the experience of looking for that key date to finish a series. Key dates are coveted coins that make a set go from ordinary to extraordinary, while expanding and permanently changing coin collections for the better.

The key to success in collecting and investing is to purchase a variety of key date coins to balance out a well-diversified rare coin portfolio. Key date coins will appreciate in value over time because of their limited supply and increased demand.