2014 was a lousy year for global value investors. Cheap markets, as measured by the cyclically-adjusted price/earnings ratio (“CAPE”) got even cheaper, while expensive markets got even pricier. (Note: the CAPE takes a ten-year average of earnings as a way of smoothing out the economic cycle and allowing for better comparisons over time.)

I expect this to reverse in 2015. At some point–and I'm betting it could be as early as the first quarter–global market valuations should start to revert to their long term averages. That's fantastic news if you're invested in cheap foreign markets. It's not such fantastic news if your portfolio is exclusively invested in high-CAPE American stocks.

Let's take a look at just how skewed the numbers are. The S&P 500 managed to produce total returns of 13.7% in 2014. But as quant guru Meb Faber pointed out in a recent blog post, globally, the median stock market posted a loss of 1.33%. The cheapest 25% of countries saw declines of 12.88%, while the most expensive markets actually gained 1.36%.

I should throw out a couple caveats here. These were the returns of u.s.-traded single-country ETFs, which are priced in dollars, and not the national benchmarks. The strength of the U.S. dollar relative to virtually every other world currency last year was a major contributor to the underperformance of the rest of the world.

All the same, it's worth noting that we're in uncharted territory here. As Faber noted in a recent tweet, U.S. stock valuations relative to foreign stock valuations closed 2014 at the highest spread over the past 30 years. Four out of the five biggest relative valuation gaps resulted in outperformance by foreign stocks the following year. The only exception was 2014.

Let's dig into the numbers. The CAPE for the S&P 500 is now 27.2. That's a full 63.9% higher than the historical average of 16.6, more expensive than at the 2007 peak, and close to the 1929 peak. The only time in U.S. history where the S&P 500 was significantly more expensive based on CAPE was during the peak of the 1990s tech bubble.