It is not. The only entry point is for the black market people to speculate. What is happening is that the black market people set the rate and government tries to move to meet the level of the black market people. Because they are parallel lines, government chases the black market, and the black goes up and it is an endless thing. We did not just get here by accident.
Government has to regulate exchange control.
We have to prohibit or criminalise those who buy dollars and take out the manner that the people are doing. Banks are buying from official rate and re-cycling. Individuals who have money in naira are converting it to dollars to take out of the country because the exchange rate regime is liberalised. You can re-commerialise it. Fix a rate for the naira and ensure it does not go outside that.