Many analysts are pointing to Friday, December 4, as the day that logic returned to the forex markets. On that day, the scheduled release of US non-farm payrolls indicated a drop in the unemployment rate and shocked investors. This was noteworthy in and of itself (because it suggests that the recession is already fading), but also because of the way it was digested by investors; for the first time in perhaps over a year, positive news was accompanied by a rise in the Dollar. Perhaps the word explosion would be a more apt characterization, as the Dollar registered a 200 basis point increase against the Euro, and the best single session performance against the Yen since 1999.

Previously, the markets had been dominated by the unwinding of risk-aversion, whereby investors flocked back into risky assets that they had owned prior to the inception of the credit crisis. During that period, then, all positive economic news emanating from the US was interpreted to indicate a stabilizing of the global economy, and ironically spurred a steady decline in the value of the Dollar. On December 4, however, investors abandoned this line of thinking, and used the positive news as a basis for buying the Dollar and selling risky currencies/assets.

If you look at this another way, it reinforces the notion that investors are paying closer attention to the possibility of changes in interest rate differentials. The fact that the recession seems to have ended suggests that the Fed must now start to consider tightening monetary policy. This threatens the viability of the US carry trade – which has veritably dominated forex markets – because it literally increases the cost of borrowing (carry): “If the market thinks that Fed rates are about to move higher, the dollar will cease to be a funding currency and the inverse correlation between the dollar and risky assets will break.”

To be fair, it will probably be a while before the Fed hikes rates: “It’s a prerequisite to have a continuing decline in the unemployment rate for at least three months before the Fed considers tightening,” asserted one analyst. At the same time, investors must start thinking ahead, and can no longer afford to be so complacent about shorting the Dollar. As a result, emerging market currencies probably don’t have much more room to appreciate, since the advantage of holding them will become relatively less attractive as yield spreads narrow with comparable Dollar-denominated assets.

To be more specific, investors will have to separate risky assets into those whose risk profiles justifies further speculation with those whose risk profiles do not. For example, currencies that offer higher yield but also higher risk will face depressed interest from investors, whereas high yield/low risk currencies will naturally greater demand. You’re probably thinking ‘Well Duh!’ but frankly, this was neither obvious nor evident in forex markets for the last year, as investors poured cash indiscriminately into high-yield currencies, regardless of their risk profiles.

To be more specific still, currencies such as the Euro and Pound face a difficult road ahead of them (as does the US stock market, for that matter), mainly due to concerns over sovereign solvency. (Try saying that three times fast!) On the other hand, “Commodity-linked currencies such as the New Zealand, Australian and Canadian dollars [have] rallied sharply, and will probably continue to outperform as their economies strengthen and their respective Central Banks (further) hike interest rates.

It remains to be seen whether investors will remain logical in 2010, since part of the recent rally in the US Dollar is certainly connected to year-end portfolio re-balancing and profit-taking, and not exclusively tied to a definitive change in perceived Dollar fundamentals. Especially since they remain skittish about the possibility of a double-dip recession, investors could very easily slip back into their old mindsets. For now, at least, it looks like reason is in the front seat, making my job much less complicated.