Positive USD/Pula currency movement The Botswana Pula has during the last months deprecated against the USD. This is a positive thing for Lucara who has expenses to pay in Pula and the income is in USD.
Currently the USD/Pula ratio is 11.72 .
https://tradingeconomics.com/botswana/currency
So, currency does not seem to be able to explain the share price.