How come coins before 1970 are always going up in value year by year but coins after 1970 are still worthless unless mint state or proof? It seems like it will take longer for them to go up in value than the older ones.
Coins that are not gold or silver follow a supply /demand curve, and the newer the year, the less the curve will go up unless, there was a limited number of the coins produced. The same curve will be apparent in the various years of a series. The more of the coins saved, the lesser the price and the reverse. This also applies to grades within a specific year. The 1931-D cent is less than the 1931-S cent in all grades to about MS64-65, where it changes and the 31-D is more costly because more people saved 31-S than did the 31-D, so a higher grade coin is rarer in 31-D. For Silver and gold coins, the price of precious metals during the 80s and now have caused a decrease in the number of such coins as they often have a melt value higher than the PM. But this issue is far from resolved , so we won't knoiw relative value for some time in the future, IMO. Welcome to the Forum. Jim
In general, post-1964 coins (excluding 1965-1970 Kennedy Halves and some coins made for collectors) have very little intrinsic value. Unless the coins are in high mint state they are usually worth only face value.