RE:RE:RE:RE:RE:RE:RE:RE:RE:RE:RE:Marc Of course... I can speak from experience that "common sense" isn't always apparent in many accounting standards. I reference Wikipedia links below, where possible, because most accounting industry source documents can be long and not easily understood (like trying to read legal documents if you aren't a lawyer).
1. for starters: International Financial Reporting Standards (IFRS) issued by the IFRS Foundation and International Accounting Standards Board. https://en.m.wikipedia.org/wiki/International_Financial_Reporting_Standards
this represents accounting industry's oversight body responsible for setting regulations for most jurisdictions in the world, including Canada.
2. IFRS 9 specifically accounts for financial instruments. https://en.m.wikipedia.org/wiki/IFRS_9
I noticed when reviewing this link to post that my original post was accurate, but missed some potentially relevant info. In many cases, equity holdings are re-evaluated periodically (as I described, which likely led to the $50 unrealized loss being reported) in accordance with IFRS 9, but there are specific cases where equity holdings can be accounted for at their original cost (also in accordance with IFRS 9, and which would have likely led to an unrealized loss of around $350m as indicated in other posters' messages if used for BB accounting purposes).
Feel free to follow the bouncing ball to the original IFRS guidance documents, if you don't trust Wikipedia. Generally speaking though, I feel that Wikipedia does a good job of explaining this subject in layman's terms.
Cheers,
mas75