First, the company sells the dollar to the bank by means of an instrument called
“forward”, or, abroad, “non-deliverable forward (NDF)”. It is the traditional
dollar forward sale, by means of which the company sells dollars in one day in
the future at a preset quotation. [...] the company also performs another coupled
transaction: it sells the dollar again to the bank in the future and by means of a
risky sale of call option. In that instrument, the bank pays a certain amount to
the company in order to have the right of buying the dollar to a preset quotation
in the future