On the-privateer.com it states, " In any discussion of the future of Gold, or of the price of Gold, the first thing that must be realized is that Gold is a political metal. In the true meaning of the word, its price is "governed".
"This is so for the very simple reason that Gold in its historical role as a currency is fundamentally incompatible with the modern worldwide financial system."
Throughout history, up to August the 15th 1971, in fact, there has always been a link between paper money and gold. The history of money is littered with the connections. Either gold itself was used as a currency, or if paper was used it was backed by or represented a value of gold.
Since that fateful day in August 1971 however, the successful action of having a medium of exchange was dropped and paper itself was called upon to represent value. But paper currencies hinge on the concept that the debt on which they are based will be repaid. The only way this is being done currently is with more paper money.
Richard Russell, editor and publisher of the Dow Theory letters commented in a recent post on his website:
"Quotes are great if you own stock in a public company in a big bull market. But the great majority of amateur investors make more money holding their homes over the years than they ever make in the stock market. And the reason is that if they own a home over the years, and that home is sensibly financed, they aren’t scared out their home by those damnable quotes during bear markets.
Holders of gold might mull over the same concept. Sure gold is quoted every hour of the day around the world. Long-term holders of gold might do well to ignore the quotes. If gold doubles in price, so what? -- are you going to swap your gold for paper? If gold drops by a third, so what? – are you going to dump your gold for paper?
Why not just relax and hold your gold? Hold your gold – why? The reason is that gold is the only true money, it's the only money that remains wealth no matter what happens in the world. Gold is wealth during the biggest boom and gold remains wealth during the worst depression. So why dwell on the daily dollar price, even though gold is quoted everywhere every hour of the day? Forget the bloody quotes, just accumulate gold. It's a good thing to have in today's unstable world."
So in short, that answers the question, why buy gold and when to sell gold.