At the same time, the lines between who is a coin collector and who is a speculator or an investor are being blurred. Not only does this impact what you may already own, but it also challenges you to locate even the most common coins that may be needed to complete a series. Particularly high-grade circulation strike coins are likely to avoid the melting pot, and so are key date coins. And, just how high a grade will a coin need to be in order to survive being relegated to the melting pot? Yes, there are still enormous numbers of common dates, common date coins out there.