The S&P 500 has stunk, but these funds are red hot
Jian Wan | Vetta | Getty Images. Biotech company Tesaro's sale process is unlikely to result in a deal, sources familiar with the situation told CNBC. · CNBC

If you've been wondering how you could have made more than the sub-1 percent return generated by the S&P 500 in the first quarter, here's your answer: You should have been buying biotech and health-care funds.

In the first quarter, 10 of the top 20 best-performing mutual funds have been health care-related, according to Morningstar. Seven of the top 20 exchange-traded funds have also been in the health-care space-mostly biotech and pharmaceuticals-according to First Bridge Data, an ETF data and analytics company.

"Health care has been the place to be for the last few years," said Russel Kinnel, Morningstar's director of manager research. "There's been a lot of mergers and a lot of excitement around biotech, and you're continuing to see that."

The best-performing health-care fund is Fidelity's Select Biotechnology Portfolio (NASDAQ:FBIOX-O), which, according to the company, invests at least 80 percent of its assets in businesses that are engaged in the "research, development, manufacture, and distribution of various biotechnological products." The fund has returned 18 percent year-to-date as of March 31.

Investing in Japan was the other big outperformer among fund investing themes in the first quarter, with 5 of the top 20 mutual funds tracking Japanese stocks.

The Matthews Japan Fund (NASDAQ:MJFOX-O), a fund that invests at least 80 percent of its assets in common and preferred shares of Japanese-based companies, is also up 18 percent as of March 31.

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Why the outperformance? The country has been undergoing economic reforms, including a quantitative easing program, which helps support stock prices and depreciates the yen-it's down 14 percent over the last 12 months, and that helps exports. Lower oil prices are also a boon for the country, as it's an oil importer.

While leveraged exchange-traded funds were excluded from this data set, taking double the risk on Japan in the first quarter would have paid off. The Rydex Japan 2x Strategy Fund (NASDAQ:RYJSX-O) returned 25.5 percent. It offers 200 percent exposure to the Japanese stock market.

The top-performing fund ETF was the Market Vector's ChinaAMC SME-ChiNext ETF (NYSE Arca: PEK), tracking the 100 largest and most liquid stocks from the Shenzhen Stock Exchange's small- to mid-cap universe. The ETF is up 47 percent since January-in part because it's one of the only ETFs to take advantage of China's A-Shares market, which only opened to foreign investors in November. The ETF itself was created last July.