Unlimited future downside? Really? I would like to know on which context this is possible.
I don't know in which context the writer is writing, I'm a developer and have been mostly working on startup-style projects. If you fail, you don't make a buck, the product does not work or does not sell. The downside is the lost time and money.
I have also known couple of startups, which have had really good engineers who have invested lots to testing, maintainability etc. In the end however the business hasn't succeeded selling the product, and all that investment was worth essentially nothing.
I was trying to make an ironic joke about the pitfalls of metaphors by using a metaphor. It didn't really have anything to do with the premise of the origīnal post. So I apologize for being off-topic - the opportunity was just too tempting :)
Actually, I think the commentator here assumed (as I did) that you were slightly off-topic talking about the use of metaphors in software programming. I feel a little bit silly now, FWIW.
There's also no unlimited downside in finance -- eventually you can't take out more debt, can't pay the interest, and default (creating counter party risk).
I suppose net across the system, you could inflict more downside to others exposed to your default, but it's not unlimited unless you can wipe out the entire planetary economy (financial and non financial) with your bet.
In the normal case of short selling (absent a large enough position to be subject to a short squeeze) future downside is not unlimited; your broker will close your position unless you put up enough capital.
