FX Value - PPP Strategy

Purchasing power parity (PPP) is a theory concerning the long-term equilibrium exchange rates based on relative price levels of two countries. The concept is founded on the law of one price; the idea that in absence of transaction costs, identical goods will have the same price in different markets. Different countries of course consume different baskets of goods, but it is partially possible to asses relative price level (to assess which country is „cheaper“ and which is „more expensive“ for living). PPP theory then says, that price differences between countries should narrow over time by exchange rate movements or by different speeds of inflation (which also has some implications on exchange rate movements).

Fundamental reason

As it was already mentioned - different countries consume different baskets of goods and it is partially possible to asses the relative price level. Price differences between countries narrow very slowly over time. A rebalanced portfolio which has the actual most undervalued and overvalued currencies helps to capture gains from exchange rate convergence to fair value.

Markets traded
Confidence in anomaly's validity
Notes to Confidence in anomaly's validity
Period of rebalancing
Notes to Period of rebalancing
(or Monthly)
Number of traded instruments
Notes to Number of traded instruments
it depends on investor's need for diversification (10-20)
Complexity evaluation
Simple strategy
Notes to Complexity evaluation
Financial instruments
futures, forwards, swaps, CFDs
Backtest period from source paper
Indicative performance
Notes to Indicative performance
per annum, performance is calculated from Deutsche Bank Currency Valuation USD Index
Estimated volatility
Notes to Estimated volatility
volatility is calculated from Deutsche Bank Currency Valuation USD Index
Maximum drawdown
Notes to Maximum drawdown
Sharpe Ratio


value, FX anomaly, forex system

Simple trading strategy

Create an investment universe consisting of several currencies (10-20). Use the latest OECD Purchasing Power Parity figure to assess fair value of each currency versus USD in the month of publishing and then use monthly CPI changes and exchange rate changes to create fair PPP value for the month prior to the current month. Go long 3 currencies which are the most undervalued (lowest PPP fair value figure) and go short 3 currencies which are the most overvalued (highest PPP fair value figure). Invest cash not used as margin on overnight rates. Rebalance quarterly or monthly.

Source Paper

Deutsche Bank
Valuation - In the long run, currencies tend to move towards their „fair value“. Consequently, systematically buying „undervalued“ currencies and selling „overvalued“ currencies is profitable in the medium term. One of the strongest conclusions in academia is that fundamentals tend not to work for currencies in the short to medium term, yet they do long term. One of the oldest measures of „fair value“, purchasing power parity, has been shown to work in the long run.

Other Papers

Kroencke, Schindler, Schrimpf: International Diversification Benefits with Foreign Exchange Investment Styles
Style-based investments and their role for portfolio allocation have been widely studied by researchers in stock markets. By contrast, there exists considerably less knowledge about the portfolio implications of style investing in foreign exchange markets. Indeed, style-based investing in foreign exchange markets is nowadays very popular and arguably accounts for a considerable fraction in trading volumes in foreign exchange markets. This study aims at providing a better understanding of the characteristics and behavior of stylebased foreign exchange investments in a portfolio context. We provide a comprehensive treatment of the most popular foreign exchange investment styles over the period from January 1985 to December 2009. We go beyond the well known carry trade strategy and investigate further foreign exchange investment styles, namely foreign exchange momentum strategies and foreign exchange value strategies. We use traditional mean-variance spanning tests and recently proposed multivariate stochastic dominance tests to assess portfolio investment opportunities from foreign exchange investment styles. We nd statistically signi cant and economically meaningful improvements through style-based foreign exchange investments. An internationally oriented stock portfolio augmented with foreign exchange investment styles generates up to 30% higher return per unit of risk within the covered sample period. The documented diversi cation bene ts broadly prevail after accounting for transaction costs due to rebalancing of the style-based portfolios, and also hold when portfolio allocation is assessed in an out-of-sample framework.

Amen: Beta'em Up: What is Market Beta in FX?
In asset classes such as equities, the market beta is fairly clear. However, this question is more difficult to answer within FX, where there is no obvious beta. To help answer the question, we discuss generic FX styles that can be used as a proxy for the returns of a typical FX investor. We also look at the properties of a portfolio of these generic styles. This FX styles portfolio has an information ratio of 0.64 since 1976. Unlike its individual components, the FX styles portfolio returns are relatively stable with respect to underlying regimes in S&P500. Later we replicate FX fund returns using a combination of these generic FX styles. We show that a combination of FX trend and carry, can be used as a beta for the FX market. Later, we examine the relationship between bank indices and these generic FX styles. We find that there is a significant correlation in most instances, with some exceptions.

Accominotti, Chambers: Out-of-Sample Evidence on the Returns to Currency Trading
We document the existence of excess returns to naïve currency trading strategies during the emergence of the modern foreign exchange market in the 1920s and 1930s. This era of active currency speculation constitutes a natural out-of-sample test of the performance of carry, momentum and value strategies well documented in the modern era. We find that the positive carry and momentum returns in currencies over the last thirty years are also present in this earlier period. In contrast, the returns to a simple value strategy are negative. In addition, we benchmark the rules-based carry and momentum strategies against the discretionary strategy of an informed currency trader: John Maynard Keynes. The fact that the strategies outperformed a superior trader such as Keynes underscores the outsized nature of their returns. Our findings are robust to controlling for transaction costs and, similar to today, are in part explained by the limits to arbitrage experienced by contemporary currency traders.

Menkhoff, Sarno, Schmeling, Schrimpf: Currency Value
We show that measures of currency valuation derived from real exchange rates contain significant predictive content for FX excess returns and spot exchange rate changes in the cross section of currencies. Most of the predictability stems from persistent cross-country differences in macroeconomic fundamentals. This suggests that currency value mostly captures risk premia which vary across countries but are fairly static over time. Moreover, our results do not support the standard notion that trading on simple measures of currency value is profitable because spot exchange rates are reverting back to fundamental values. When decomposing real exchange rates into underlying macroeconomic drivers, however, we find that refined valuation measures relate more closely to "currency value" in the original sense in that they predict both excess returns as well as a reversal of exchange rates.

Pojarliev, Levich: A New Look at Currency Investing
The authors of this book examine the rationale for investing in currency. They highlight several features of currency returns that make currency an attractive asset class for institutional investors. Using style factors to model currency returns provides a natural way to decompose returns into alpha and beta components. They find that several established currency trading strategies (variants of carry, trend-following, and value strategies) produce consistent returns that can be proxied as style or risk factors and have the nature of beta returns. Then, using two datasets of returns of actual currency hedge funds, they find that some currency managers produce true alpha. Finally, they find that adding to an institutional investor’s portfolio even a small amount of currency exposure — particularly to alpha generators — can make a meaningful positive impact on the portfolio’s performance.