The Tan item is a cost-basis failure, and cost basis is the one thing on this page that works identically at every scale. Four financial outlets got the sign of a position wrong because they could not see the oldest tranche.

In Canada the trap bites differently and harder. Identical shares of the same class are pooled into a single averaged adjusted cost base — you cannot pick which lot you sold, the way a US holder can with specific identification. That means the oldest, cheapest tranche is dragged into every disposition whether you remember it or not, and a missing early purchase record does not just mislead you, it misstates your return on an actual filing. The same averaging applies across your non-registered portfolio, to reinvested distributions, and to shares of your own company acquired at different times.