Unless you are part of an IPO or are buying newly issued stock you are also speculating on stocks when you buy them.

Note: Not a finance person, just a personal opinion.

In practice, it may not be possible to neatly classify any particular financial decision as being purely investment or purely speculation. This only increases the need to have these words mean clearly different things so that we may use them to analyze the different aspects of the ambiguous world in which we find ourselves. Blurring the meaning of the words effectively robs people of the ability to reason about their circumstances, and it is no wonder that many people feel invested in creating such confusion.

The impossibility of separating the two concepts necessitates two different words for those concepts?

That's a contradiction.

The concepts are easy to separate: Investment is symbiotic, Speculation is parasitic. Having clear concepts is more important when the real-world examples are complicated.

Speculation isn't necessarily parasitic at all. For example it can function in assuming risk.

How is speculation parasitic?

Speculators seek to extract alpha without regard to the overall health of the instrument. Shorting is just as good as going long, so far as you make a profit.

That doesn't mean they're parasitic. To show they're parasitic, you'd have to describe how they hurt the company.

Regardless, what defines speculation is not parasitism, it's uncertainty. And there's uncertainty in any investment as well. That's why there's no clear line between the two.

I disagree. I have made a clear delineation in the semantic content of my definitions, while you continue to attempt to confuse the issue.

I mean, the definitions aren't yours to make. These words exist in the dictionary.

Writers of dictionaries are archaeologists of language. They do not prescribe the meaning of words like a programmer or mathematician. Their definitions are posterior to language. The definitions are in fact mine to make, provided they result in successful communication with people who have adopted similar definitions.

Go read my original post again. I am advocating against ambiguity in language, as this serves to obscure analysis. You are clearly happy to obliterate distinction, however, and have made no attempt at a positive argument why it is beneficial to discourse.

Language is a constant negotiation about the meaning of words, and I have made my position clear.

I'll bow out here, but I'll just point out that this is a great example of how one's adherence to their ideas makes rational conversation impossible.

We can only communicate to the extent that we agree on the definitions of words, so for you to invent your own definitions, which contradict how other people use the word, as codified in dictionaries, then there's zero hope of reaching shared understanding.

It would be absurd for me to claim that "the sky is brown", the later argue that I was right all along because I'm defining "brown" to be "blue".

I will simply point out that at every opportunity, I have been upfront about what definitions I am adopting and the distinctions I am attempting to make, while you have done nothing but dissemble and create ambiguity, without offering a positive program of your own. I will leave it up to other readers to make their own conclusions.

If I say "the sky is brown", am I being up front that I'm defining "brown" to be the color of the sky?

This comment thread has been one of the weirdest internet arguments on the semantics of a word that I've seen in a while.

only on HN.

Would you say that all short selling is parasitic?

It depends I guess on how you do your homework and how long you hold the stocks for. Warren Buffett style long-term value based investing vs speculative day trading for example.

Speculation relates to uncertainty, not timing.