In this article, we’ll take a closer look at these two categories that dominated fund flows, as well as take a look at some of the top funds in each category.

International ETFs were the biggest winners during 2015, taking in roughly half of all capital inflows across all funds. With the U.S. raising interest rates, investors flocked to regions and countries that plan on continuing their monetary easing. The biggest winners were currency-hedged ETFs that focused on taking advantage of diverging monetary policies around the world, particularly in the European Union where easing continues.

Despite China’s turmoil towards the end of the year, the Market Vectors China SME-ChiNext ETF (CNXT ) was one of the top performing international ETFs of 2015, rising 42.15%. The WisdomTree Japan Hedged Healthcare Fund (DXJH C+) soared 37.68% thanks to the country’s reasonable equity valuations, while the iShares MSCI Ireland Capped ETF (EIRL B+) rose 20.43% in 2015, driven by the country’s robust economic recovery.

Many traditionally liquid ETFs experienced significant outflows throughout the year but low-cost and smart-beta ETFs picked up the slack. By adjusting passive indexes based on factors like volatility or momentum, smart-beta ETFs aim to outperform their passive counterparts while keeping costs low through automation. Currency-hedged ETFs also attracted a lot of capital since they removed the currency risks associated with foreign equities.

The most successful smart-beta ETFs in 2015 included the WisdomTree Europe Hedged Equity Fund (HEDJ A-) and the Deutsche X-Trackers MSCI EAFE Hedged Equity ETF (DBEF B+), both of which took in more than $10 billion a piece. Currency-hedged ETFs as a whole took in more than $50 billion throughout the year after the Federal Reserve’s decision to hike interest rates. The move towards smart-beta funds also helped iShares beat out Vanguard in total fund inflows.

ETFs took in about $238 billion in 2015, nearly matching their record inflows, with international and smart-beta funds taking the lion’s share. In general, once-popular liquid ETFs are being replaced by low-cost and smart-beta options, while investors are also positioning themselves to avoid the currency risks associated with divergent global monetary policies. These dynamics led to iShares and Vanguard being the top destinations for capital in the world of ETFs.

These movements should continue moving into 2016 as the same macroeconomic trends remain in force. In the U.S., the Federal Reserve indicated that it would slowly raise interest rates as long as fundamentals remain in place. In Europe, the ECB is likely to continue monetary easing in order to combat deflation. And in Japan, the Bank of Japan may finally be forced to take more dramatic measures to improve the economy and stem deflation.