Latest figures of FDI flows to Nigeria show a decline of 27 per cent from $4.7 billion in 2014 to $3.4 billion in 20152, representing its lowest value since 2005. This decline is largely attributed to the oil price slump, which has generally increased uncertainty in the economy, with adverse effects on investors confidence. The fall in FDI flows was witnessed in most resource based economies in Africa, as FDI flows to the continent fell by 31 percent in 2015. The forex controls in place in Nigeria has also exacerbated the uncertainty in economy, and created obstacles for both domestic and foreign investors. Thus a review of the forex restrictions could send positive signals to investors.

This study examines the hedging effectiveness of portfolio investment diversification between developed and developing economies; with focus on the Nigerian stock asset vis--vis the stock assets of the United States (US) and United Kingdom (UK). Its main contribution is in the analysis of optimal portfolio diversification using optimal portfolio weight (OPW) and optimal hedging ratio (OHR). Empirical findings show that the OPW and OHR are low, which indicates impressive potential gains from combining Nigerian stock assets in an investment portfolio with US and UK stock assets. In addition, exchange rate volatility is found to pose stern limitation on the potential benefits of this portfolio diversification arrangement. It is therefore recommended that the monetary authority in Nigeria should pursue policies towards reducing exchange rate volatility to the barest minimum. This will possibly attract more investors from developed economies who might be willing to combine Nigerian stock in their investment portfolio to minimize portfolio risk.

The paper presents an elaborate econometric analysis of a number of key macroeconomic indicators to oil revenue and examines the results of oil revenue fluctuations.