What do you say an investment is, what "investment" means in a financial context, then we can consider whether gold is an investment. — tim wood

An investment is something you purchase not to make use of, but with the hope it will make you money passively, just by owning it. This can come from appreciation in price over time, or from income in the form or rent or dividends, or both.

The question before us is whether buying gold to hold passively for eventual resale is an investment or speculation. From a little bit of searching, I'm satisfied - and surprised - that the words themselves are so loosely defined and used that no argument over just the words can prosper either side although the words retain some descriptive value.

To me, an investment is the placement of an asset, most often money, for such uses as will add value/profit for the investor, realized as revenue or at resale (or both). Speculation, on the other hand, is as you say, buying something simply to hold in the hope that someone will buy it for more, later. And at least a couple of distinctions hidden here. Investment is about the use of assets to create income, value, and profit. Speculation is about money and the hope for more money.

Land may be a helpful example. A developer, seeing land he thinks is not being put to highest and best use, may buy it and develop it and profit from his investment. Another fellow seeing the same land might buy it and do nothing with it, in the hope that someone will buy it from him at a higher price. And this latter person is usually called a speculator.

And the trick is value. All else being equal, how does speculation add or produce value? And the answer is that it does not. And in terms of both land and gold and most other speculations, the speculator buys retail, sells at wholesale, pays a variety of costs, and then pays taxes on proceeds. Thus speculation usually such a poor investment it is no longer called an investment, but instead speculation.

And to be sure, occasionally people win at speculating, just as sometimes people win at a casino. But the "game" is so stacked against them that it doesn't happen very often, and luck plays a large part.

In sum, "speculation" and "investment" are used sometimes without clear distinctions between them. In the details, they're very different.

From a little bit of searching, I'm satisfied - and surprised - that the words themselves are so loosely defined and used that no argument over just the words can prosper either side — tim wood

Really all that needs be said.

But are cryptocurrencies truly scarse at all? — hypericin

They range from supplies of 1 to (theoretical) supplies of infinity.