Yes, it is US dollars.
Why should you assume $ refers to USD?
Because the US is the global superpower. Trade and banking reserves overwhelmingly use USD.
No other currency, and certainly none that use the $ symbol, even come remotely close to the USD.
I particularly hate businesses which sell stuff internationally who put $ on their website rather than US$ / AU$ / etc. You can’t assume that just because it is an American company that $ means US$, because some (but far from all) American companies detect the customer is coming from Australia/Canada/whatever and automatically display localised prices. And don’t get me started about the websites that seem to be offering too-good-to-be-true deals on Australian hotels until I realise they are actually showing US dollar prices, but $ instead of US$ makes that non-obvious
To 95% of the world, the relevance and influence of USD isn’t remotely close to their own currency’s. Sure, it’s relevant to some industries and to the larger economy – that makes it like CNY or EUR are to you, nothing more.
I do think a USD assumption is reasonable, but only because the statement was made on HN, which is predominantly American. USD does not own the $ symbol outside of the US.
Of course, a Canadian or Australian, or New Zealander, or Rhodesian, or Zambian, whose local currency also uses the same symbol, will tend to assume their local currency instead. But they are a minority of the world's population.
Especially on a thread specifically talking about currency conversion.
That is not true. For example on foreign exchange markets "Dollars" means USD. If you want AUD it's "ozzie", and if you want CAD it's "Loonie"[1], and NZD is "kiwi".
[1] I don't make the rules - FX markets are weird. https://en.wikipedia.org/wiki/Loonie
It does merit discussion. This has been demonstrated. The parent shouldn't be downvoted for pointing out the ambiguity to an actual global population that exceeds the United States of America by some margin. It's not about being a "superpower" it's about clarity of communication and eyeballs.
Just like the date 04/10/2024. Is that a few days ago, or in a number of months? Wheras 2024-10-04 makes it explicit (in a sane way that denotes a clear hierarchy of values).