In 2010, financial advisor and stock analyst Marcio Silveira went to see some old friends at a conference on investing in Brazil hosted by the New York Society of Security Analysts. He had grown up in Brazil—his father was a financial analyst and they had dinner table discussions about the markets.

He remembers that people at the conference were “super excited” about the country—its structural reforms and improved fiscal policies. “Brazil is on track to see economic growth that could rival India and China,” said the conference press release.

“They were talking about Petrobras in the same league of Exxon,” says Silveira, “and they were talking about valuations sometimes being even higher than the developed markets here because you have not that much risk and maybe better growth prospects. And some questions were pretty basic coming from an audience that was very uninformed. At that point I was really scared and I felt like OK.… Maybe Brazil is too hot.”

As it happens, he said, that exuberance coincided with the top of the market. “Around the middle of 2013, there were many demonstrations in Brazil and the entire economic mood became very gloomy,” he says. Since the conference, the iShares MSCI Brazil Capped ETF has fallen some 35%.

Emerging market countries saw trillions of dollars snow down on them after the financial crisis in 2008, when investors hungering for return turned away from ailing developed markets. But in 2013, it took a couple of Fed comments to create an ugly reversal of fortune. The end of quantitative easing and hints at higher interest rates sent investors skipping away fast from the developing world. Currencies depreciated. Capital flows ebbed. Equity prices sank. In the month after the Fed made its comments on May 22, 2013, the iShares MSCI Emerging Markets ETF saw $6.6 billion in outflows, while the Vanguard FTSE Emerging Markets fund saw almost $2.6 billion spill out, according to ETF.com. (Both were in the top five of redemptions for the year.) In one week in June of last year, the iShares fund reportedly accounted for half of all ETF outflows.

Some $29.2 billion reportedly spilled out of emerging market funds last year.

Once tempers cooled, emerging markets changed again around February of this year, and they were doing well enough that the MSCI emerging markets index even outpaced the S&P 500 until September. But people are now worried that with fresh announcements ahead from Janet Yellen & Co., the emerging markets could be vulnerable again. After an upswing in 2014, the Institute of International Finance said that emerging markets capital inflows saw a sharp decline in inflows between August and October of this year.

The 2013 ebb was extremely punishing on India, Brazil, Turkey, South Africa and Indonesia, whose currencies Morgan Stanley called the “Fragile Five.” These countries, seen as being too thirsty for foreign nourishment for their growth plans, saw their stock markets on average fall 13.75%, according to an IMF working paper published in June of this year by authors Prachi Mishra, Kenji Moriyama, Papa N’Diaye and Lam Nguyen.

But other countries did better. The IMF report, called “The Impact of Fed Tapering Announcements on Emerging Markets,” said the countries less sensitive to loose Fed lips boasted certain fundamental strengths: “In particular, countries with larger current account surpluses, stronger fiscal balances, lower inflation and more reserves saw smaller depreciation in their exchange rates and a lower rise in bond yields. Countries with deeper domestic financial markets were less affected as the size of these markets meant that investors could move large amounts of capital outside the country or toward other domestic markets without significant changes in prices.” In addition, countries more tied to China weathered the post-FOMC volatility better, said the paper.

“These are mainly countries in the Asian supply chain.”

Silveira, once a stock analyst covering these countries and now a financial advisor, says nervous investors are often heedless of those fundamentals.

“On the strong side we have Korea, Russia, China, countries that run a current account surplus. They don’t depend on foreign money to pay their bills. And they have a very high level of reserves. … But then you see countries that are a lot more vulnerable like Turkey, South Africa, Brazil, India that run current account deficits, and they have relatively lower levels of reserves.”

“Foreign economies (and their equity markets) that are often hit worst when interest-rate shocks occur are those with large current account deficits (countries that are importing more than exporting,)” says Carl Macko, president of Synergy Capital Management in Atlanta. “Countries with high external borrowings have to pay back these creditors with a depreciating currency (due to an outflow of capital to countries with higher real interest rates).  However, external borrowings relative to reserves are much smaller today than during the Asian financial crisis of the 1990s. Emerging economies (especially Latin ones) have five to 10 times as much in foreign reserves to pay creditor nations.”

Still, it seems, these stocks tempt hot money and provoke extreme temperaments—reactions either over-exuberant or too fraidy cat. The stocks are volatile, even fans admit, but that’s why they promise a premium for long-term investors. The point is having the guts to stick it out year in and year out.

And you ignore these markets at your peril. Indeed, reports by Citibank, for instance, say that 70% of global growth in the upcoming years will come from emerging markets countries. Plenty of advisor fans feel that last year’s emerging market tumble was an overreaction, and that the sector is still a paradise of bargains.

According to JP Morgan Asset Management, the forward P/E ratio for the emerging markets index was only 10.9%, while it’s 15.9 for the United States and 14.2 for the MSCI All Country World Index as of September 30 of this year. (But within the emerging market countries, those valuations are all over the place. South Africa’s is 14.5. Mexico’s is 18.4 and India’s is 16.4, where China’s forward P/E is 8.8 and Russia’s a low 4.7.)

Buying low and selling high has paid off, says one advisor.

“At the end of last year, no one wanted emerging markets,” says CFP Bobbie Dow Munroe, the owner of Fraser Financial in Atlanta.

“During a great year for domestic equities, their performance was simply pitiful. So one could look at this year’s performance and simply see it as a catch-up year after 2013. Emerging markets were some of our most common purchases 10 to 12 months ago as we rebalanced client portfolios. … Indeed, two of our favorites have done quite well versus U.S. equities.”

Munroe uses a core index strategy, but she says some funds are too Europe-centric, and thinks Pacific Rim and Latin American funds are set to outperform. As of August 31, two funds she uses had seen big growth for the year: the iShares Latin America 40 fund (ILF) was up 20% and the iShares MSCI Pacific Ex Japan (EPP) was up 11%. Those countries are set to benefit more from an emerging middle class, she says. “Europe is basically a developed economy.” In the overall, she sees emerging stocks as the future (noting that the United States was an emerging market 100 years ago).

But playing indexes instead of active managers is controversial, even among emerging market fans, since index funds can be top-heavy with certain sectors (like commodities) or countries (like China) that may miss the point of the burgeoning middle-class consumer. Munroe admits that it’s hard to get that perfect broad-based diversified emerging markets fund. “Because that’s just not the way they come. It’s like going to shop at 7-Eleven instead of going to Publix. There’s not as much on the shelf. If you go to 7-Eleven, you’re going to end up with pork rinds and orange soda.”

The tapering talk has been going on a while, Silveira says, and thus his feeling is that a lot of the vulnerability has already been priced in, maybe excessively, to emerging markets prices. Though there is also a worry that a stronger dollar will hurt emerging markets, Munroe notes it would also hurt companies like Coca-Cola.

There are still sector skeptics. Louis Kokernak, the head at Haven Financial Advisors in Austin, Texas, says flatly that emerging markets are a better buy now than the U.S. stock market given the P/E and price-to-book ratios (and he uses a core index approach along with some extra funds such as a DFA value strategy). But he also says the emerging markets are on probation for him. In part that’s because there’s a disconnect between GDP growth and the stock market growth in countries such as China, and given the liquidity and the cost, he’s comfortable overweighting in the U.S.

“If you look at long-term data going back to the 1970s, a portfolio that’s about two-thirds to even 80% U.S. stocks is pretty close to being optimal.” He continues to recommend that clients have 65%-70% here at home and says that U.S. investors wanting to exploit overseas markets can do it through domestic multinationals. He says if you want to get exposure to the emerging Chinese middle class, you’re better off investing in Starbucks, Boeing or IBM.

Bryan J. Polley, with Allodium Investment Consultants in Minneapolis, says that his firm is using both index funds and active funds.

“The index funds will do well while the valuations return to normalized levels,” he says. “The active managers have an advantage in this market as panicked or frustrated investors sell indiscriminately, leaving some excellent companies undervalued and set up for easy picking.”

Doug Wolford, the president and COO of Convergent Wealth Advisors, which manages $11 billion for individuals and family offices, says his firm sees bargains in these countries and his firm has overweighted them for some time where there’s strong growth stories.

“Sentiment was overly negative based on China” last year, says Wolford, who works in Convergent’s Washington, D.C., office. “There’s such a tailwind for emerging markets as a long-term play, it’s difficult not to overweight that asset class right now.” He says his typical client has 15% to 20% in emerging markets. The firm starts with actively managed funds that have people on the ground in these countries, but he has also started investing in private equity investments because of the surplus of opportunity.

He speaks of Japan, where there are a lot of companies run by people whose kids will want to sell, which creates buyout opportunities. Though Japan isn’t an emerging market, Wolford says those same plays are available in other Asian markets.

He points to other emerging countries like India, which he says has a large, growing consumer base; an educated population; a new pro-business leadership (in prime minister Narendra Modi); and manufacturing and tech opportunities. What’s more, the country has become more integrated with the rest of the world.

“Tata [Motors] owns Range Rover now, for heaven’s sake, so you’re really getting companies that used to be more purely Indian becoming multinationals,” he says. “That’s a really good sign for business.”

But volatility is still important to consider, and the most conservative investors won’t have it.

Mark Wilson, chief investment officer with the Tarbox Group in Newport Beach, Calif., says his firm invests in emerging markets through the PIMCO EM Fundamental IndexPLUS AR Strategy Fund (PEFIX), a fundamental index (run in part by Rob Arnott and Research Affiliates) with a bond portfolio wrapped around it. Wilson says he doesn’t use emerging markets for his most conservative investors because the ups and downs are going to be too steep for them.

“Those clients are going to want to sell every time [emerging markets] go down a couple of digits,” he says. “If we can’t hold their hands through the process, we’d rather not even own it because they are going to want to sell it at the worst times and buy at the worst times.”