Why Do Graded Coin Values Mostly Seem To Decrease In Value Over Time?

i agree with CarrsCoins. its all about supply and demand just like any other commodity. there are two types of collectors. one are collectors and the other are investors or a combination of the two. if you're a collector you are buying coins to fill a hole in your collection most of which are common. with the decline in generational interest common coins are going to be common coins pretty much forever and the prices will reflect that. rarer coins are going to be purchased more so by investors. folks that may be collectors but purchase these coins to increase in value over time. rarer coins in higher grades are always going to be in demand, however, prices of these can exceed what they typical collector can pay so this limits demand and in turn holds down the prices. however, if you look at the prices of lets say MS65 morgans you will see that that over the last couple years they have increased considerably but when you get to that level and prices investors want to ensure that the coin itself is in fact that grade so they for the most part avoid buying them raw and you can see this in demand for slabbed high grade coins.

bottom line...if you want to see increases in values in your coins over time buy high grade slabbed rarer coins.

what constitutes rare and high grade is relative.

for early copper (and many other coins) rarity is discusses using R#s.

R-8 is 1-3 copies known.
R-7 is 4-12.
R-6 is 13-30.
R-5 is 31-75.
R-4 is 76-200,
R-3 is 201-600
R-2 is 601-2,000
R-1 is more than 2,000

coins that many people consider rare like the 1916-D dime or the 1909-S vdb cent would be listed as R-1 in this scale and labeled as common. their supply is outstripped by the massive demand for those coins. they demand a significant premium.

on the flip side there are quite a few large cent variations that are R-4 and R-5 and carry no significant premium. there arent 200 people collecting them by variety. there is more supply than demand even though they are quite a bit rarer than those 20th century key dates. if 500 people start seriously collecting large cents by variety all of the R-3 coins start commanding premiums. if half the current sets are sold and nobody replaces that demand then some of R-6 coins wont be much more expensive than common coins.

condition can be relative too. my avatar picture is of an 1800 Half Dime. it is a unique die combination (the LM-5 die marriage) and the only known version of that coin. its worn slick and has a hole in it. it is the finest known example of that coin. its also the worst known. it takes one coin surfacing for that coin to no longer be top pop.

I am not sure how far away you are from the border with New Hampshire, but it might be worthwhile for you to check out the New Hampshire Coin & Currency Expo, https://nhcoinexpo.com/
Next one is April 7-8, 2023.

And here is the one from 1970.



Had you bought in 1970, you would be doing ok. However, had you bought in 1989 you would be totally underwater.

Certified coins of the same grade can be of varying quality. Many of today's collectors want coins that are solid or premium quality for their assigned grade and CAC will verify previously graded coins to be a solid/high quality example for that grade. There are many coins that are certified accurately for their grade. Unfortunately, it is an inescapable reality that many are at the lower end of the quality range for the assigned grade. CAC's rejection of a coin does not necessarily mean that CAC believes the coin has been over-graded. It simply means that there are other coins with CAC stickers that are of higher quality for the grade. CAC will eventually reject tens of thousands of accurately graded coins. The CAC green sticker also adds to the value and demand. And now they are doing their own full grading in slabs.

@NumisEd Yes that info would be helpful if someone perhaps is collecting quite a large batch of those classic coins that make up the index which I posted a link to earlier. Otherwise I guess you can visit specific price changes (for PCGS coins only) over time by cllicking the price changes link. I mentioned one for quarters earlier but below is where to find it on a PCGS price page. A person who mainly was buying say modern top pop coins and holding for example wouldnt get much data out of that index and further may have done poorly investment wise since those are among the coins that have the biggest chance to drop quite alot over time.

There is a CAC certificate lookup for stickered coins https://www.caccoin.com/lookup/

Why can't I use the CAC Verification Search to look up a PCGS or NGC graded coin that has no CAC sticker to find out if it has already been reviewed by CAC?

Many coins that CAC has reviewed, but did not sticker, have been accurately graded by PCGS or NGC. However, CAC stickers only coins that are solid for the grade, often referred to as B quality coins, and those that are considered high-end for the grade, which are often called A quality coins. Those that are accurately graded by PCGS or NGC, but are considered low-end for the grade and often referred to as C quality coins, are not stickered by CAC.

Furthermore, CAC wishes to protect the interest of an owner of a coin that has been reviewed by CAC but did not receive a sticker. Therefore, CAC does not want to compromise the value of such a coin by disclosing a negative review by CAC.

There have been many fine points explaining why the price of top graded slabbed coins decrease but here are a few more I can offer:

A) The standard for proof coins is much higher than 40 years ago. This is due partly to the very success of the grading system instituted and institutionalized by the grading companies. Therefore it is far easier to get PF 69 from many countries issued today rather than 100 years ago.

B) High grade uncirculated common circulating coinage goes for higher prices than many proofs because these coins are used and most don't fuss over looking for top grades in circulation or mint sets because the return remains low for the effort it takes to find high quality gems. And it is usually NOT worth the cost of grading such coins for the risk of not getting a high grade for it. It is usually a few years after new issues that people even consider grading a coin and these are usually from mint sets. The supply of average of mid-grade uncirculated coins usually outstrips the demand in the short to medium term. However, it seems after about a 40 - 50 year lag new collectors who view such coinage as approaching "classic" status will slowly increase demand. Examples of this happening are common circulating coins from the 60's and 70's as well as one or two denominations from the 80's and 90's (for the former, Jefferson nickels in nice unc grade or lightly circulated with full steps, Lincoln cents and Roosevelt dimes from some years and for the latter, Kennedy halves and Washington quarters from the 1990's not banged up or Lincoln cents from after 1983 that have not developed ugly toning or zinc rot).

C) TH novelty of the slab itself has worn off a little except for the earliest slabs which seem to show some collectibility. Maybe thee NCG slabs showing their new grading scale will attract colelctors just for that feature but it will likely be just for the first year or two,

D) As has been written, one should wait as the coin market is awash with people flipping coins for a fast profit. It is always best to wait before buying and even selling to catch the initial rise in price before the fall can be tricky. Best to treat coin collecting as a marathon rather than a sprint.

E) A final point, for US coins the risk of devaluation of slabbed coins after the first year is especially high as the market is fairly mature and as a predominant economic power, the tendency is for the coinage to be valued more than those countries no economically strong. There are then bargains to be found in world coinage (and not just ultra-modern as far back as the 19th century) -- coins from Iran, India, Jamaica, Venezuela, and several other countries all offer low or modest mintages and some beautiful designs. One example is a 1930 Venezualan 10 Bolivares gold coin I purchased recently. Melt value is around $1809, mintage 500,000 and for a beautiful BU Unc I paid $350 in total. A comparable coin with higher melt value ($232 1/12/2023) is the Indian Head $2.5 US coin. If we look at the 1929 issue with a mintage of 532,000 the retail of one in a similar grade (MS64+) runs at auctions over the past 3 years according to PCGS around $1,000. This example underscores the risk of slabbed US coins to fall in value due to the maturity of the market as well as access to information about other world coinage that collectors are beginning to access and share these days.