The naira depreciated by N5 to the dollar on Friday, trading N217 at the black market and N215 at the Bureau De Change (BDCs) segment of the official market.

A dealer, who did not want to be named, told NAN in Lagos that the depreciation might be due to the
closure of the Retail Dutch Auction System (RDAS) by the CBN.

It was closed by CBN on February 18.
The RDAS is a foreign exchange window at CBN where the Bureau de Change and commercial banks
buy forex.

The dealer said that the CBN’s decision, which was meant to control speculations, has made other currencies to be scarce.
He also said that dealers were left to source for forex only at the interbank market unlike in the past when they had three to four segments to buy.

Meanwhile the rate of pound also went higher. Against the N307 that it was sold for on Monday, it
exchanged for N332 against a naira.
It went for N335 at the black market, from the N314 it sold four days ago.

The naira lost N5 to the Euro to sell at N240, when compared with the N235 it sold at the BDCs on Monday.
The currency, at the black market, traded for N244 as against the N237 it traded on Monday.

source: http://www.thecable.ng/naira-hits-n217-dollar-black-market

The US knows about this.

This is not the fault of the US. It is the fault of the Nigerian government and policy makers. There is no currency risk management instruments out there. In places like the US, you have fx forwards, currency swaps,currency options and swaptions that businesses use to manage currency risk. Nigeria has none of those putting pressure on the spot market.

Unless this is done, I see the exchange rate at 225 to 250 before the year ends