NEW YORK (TheStreet) -- "To make money in the markets, you have to think independently and be humble," writes Ray Dalio in a recent piece published by Institutional Investor. What he doesn't mention: He's heavily investing in ETFs.

Just three ETFs comprise nearly 87% of Dalio's Bridgewater Associates public equity portfolio as of the end of the fourth quarter. In other words, one of the most analytical, mechanical minds in investing -- and the manager of the biggest hedge fund in the world -- is placing nearly all of his eggs in three exchange-traded baskets.

Where does Dalio have so many of his chips stacked, and should you consider them, too?

Vanguard Emerging Markets ETF (VWO) - Get Report

The Vanguard Emerging Markets ETF tracks the FTSE Emerging Index. Comprised of upwards of 900 emerging-market stocks, it is an extremely diverse vehicle. And with a 0.15% expense ratio, it is also low-cost.

As of January 31, the largest markets the ETF covers are China (24.8%), Taiwan (14.4%), India (12.6%), Brazil (9.8%) and South Africa (9.8%). Its top holdings are Taiwan Semiconductor Manufacturing, Tencent Holdings and China Mobile.

One point worth noting with this ETF is the absence of South Korean companies from the mix. VWO divested from its substantial 15% South Korea allocation in 2013 as part of a transition to the FTSE index benchmark (it previously tracked the MCSI Emerging Markets Index).

The Vanguard Emerging Markets ETF has been Ray Dalio's top holding since the fourth quarter of 2012 and as of his most recent regulatory disclosure comprises 37% of his public equity fund. Despite an unimpressive performance in recent months -- it's up about 1.5% over the past year -- the billionaire keeps betting on it and in the fourth quarter purchased an additional five million VWO shares.

SPDR S&P 500 ETF (SPY) - Get Report

Tracking U.S. market benchmark the S&P 500, the SPDR S&P 500 ETF is among the largest and most recognized exchange-traded funds in the world. Its components stretch across 25 sectors and are weighted by market capitalization. Its top holdings are Apple (AAPL) - Get Report, Exxon Mobil (XOM) - Get Report, Microsoft (MSFT) - Get Report, Johnson & Johnson (JNJ) - Get Reportand Berkshire Hathaway (BRK.B) - Get Report.

Given the S&P 500's strong run in recent years, it's no surprise SPY has proven a solid bet as well, returning 13.54% in 2014 and 32.15% in 2013. But not every year has been stellar for the ETF, which lost 36.83% in 2008 and climbed just 1.96% in 2011. From its 1993 inception through February 28, the fund returned 9.39% a year.

As for Ray Dalio, he's long been a fan of the SPDR S&P 500 ETF. Though he downsized his stake slightly in the fourth quarter, the ETF remains his number two holding, comprising 25% of his fund.

Moreover, Dalio isn't the only billionaire with an eye on SPY. 3G Capital, run by Brazilian billionaire Jorge Lemann, holds 800,000 shares of the ETF, rendering it his top holding as of the end of the fourth quarter. It looks like this may be a bit of a hedged bet, however, as Lemann's second largest position is an S&P 500 put option.

George Sorosmade headlines last year when he upped his put holdings in the SPDR S&P 500 ETF as well. He has since downsized that against-the-market bet significantly (his SPY position now comprises about 1.8% of his public equity portfolio, as opposed to more than 12% at the end of the third quarter of 2014).

iShares MSCI Emerging Markets ETF (EEM) - Get Report

The iShares MSCI Emerging Markets ETF tracks more than 800 large- and mid-cap emerging market stocks and uses as its benchmark the MSCI Emerging Markets Index. As with VWO, Taiwan Semiconductor Manufacturing, Tencent Holdings and China Mobile can be found among its top holdings. Its number one stake, however, is Samsung Electronics -- a South Korean powerhouse kept out of VWO following its 2013 benchmark switch up.

In fact, South Korea plays an important part in the performance of the iShares Emerging Markets ETF. As of March 10, it has a 14.97% weight in the fund, coming second only to China, which has a 21.85% weight. EEM has declined about 2% over the past year.

Comprising just under a quarter of Bridgewater Associates' public equity portfolio at the end of the fourth quarter, the iShares MSCI Emerging Markets ETF is one Dalio likes as well -- though perhaps not quite as much as the Vanguard fund. He pulled back on EEM slightly at the end of the year, downsizing his position slightly.

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This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.

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