How is Zakat assessed on cash held for trade if its value in one currency meets the Nisab, but its native denomination does not?

Primary text

If cash is not used to purchase anything else, Zakat is due on the cash itself, not its valuation, unlike trading goods. However, if the cash is intended for trade, Zakat is obligatory if its value in the other circulating currency reaches the Nisab, even if it does not meet the Nisab in its own form. This is because it qualifies as trade wealth whose value has reached the Nisab, thus mandating Zakat similar to trading goods.