People watch stocks for different reasons -- they're waiting for a dip in price, watching for a specific catalyst, gathering all the news and information that might affect stocks they already own, or considering a sell. Regardless of their motivation, we can better understand market sentiment by seeing who's watching what. With the Fool's free My Watchlist service, we have tens of thousands of people telling us the businesses that have, for whatever reason, piqued their interest.

With this data we have come up with a new metric, watch interest, to inform investors what stocks their peers keep tabs on in each industry. In the case of the exchange-traded fund industry, watch interest is the percentage of people keeping an eye on ETFs. By looking at what stocks people are most interested in an industry, you can get ahead of the curve by finding hot stocks that you might have otherwise overlooked. That's easy to do in the ETF industry as there are more than 1,000 publicly traded ETFs. The industry has been booming as more and more investors learn of the low-cost advantage of ETFs.

The most-watched ETF is...
Looking at the aggregate data, we see that iShares Silver Trust (NYSE: SLV) is above the rest in terms of watch interest and for good reason. As CAPS player JPAKolypse86 wrote last week:

The European default crisis will linger on for the better part of two years (at least). Continued modernization of emerging markets means that industrial demand for silver will also remain high. Those were the conditions that people mentioned when they talked about $100 silver in 2013. Little has changed since then even though some people have become more pessimistic on silver.

Here are the rest of the top 15 most-watched ETFs with their watch interest along with the stocks' CAPS rating to show the sentiment of our investing community.

 

Company

Market Cap (millions)

CAPS Rating (out of 5)

Watch Interest

1

iShares Silver Trust

$11,240

***

11.8%

2

SPDR Gold Trust (NYSE: GLD)

$59,769

**

10.9%

3

SPDR S&P 500 (NYSE: SPY)

$95,260

*

7.0%

4

Vanguard MSCI Emerging Markets (NYSE: VWO)

$51,124

*****

2.8%

5

United States Natural Gas Fund (NYSE: UNG)

$1,793

**

2.3%

6

iShares MSCI Japan (NYSE: EWJ)

$7,687

***

2.2%

7

iShares MSCI Brazil (NYSE: EWZ)

$12,579

****

1.9%

8

Market Vectors Agribusiness (NYSE: MOO)

$5,845

****

1.8%

9

Vanguard Energy VIPERs (NYSE: VDE)

$2,050

*****

1.8%

10

PowerShares DB Agriculture (NYSE: DBA)

$3,767

*****

1.8%

11

PowerShares QQQ Trust (NYSE: QQQ)

$23,919

**

1.5%

12

iShares Gold Trust (NYSE: IAU)

$7,177

**

1.5%

13

Energy Select Sector SPDR (NYSE: XLE)

$9,394

****

1.4%

14

iShares MSCI Emerging Markets (NYSE: EEM)

$39,125

***

1.3%

15

Vanguard REIT VIPERs (NYSE: VNQ)

$9,930

***

1.3%

Source: Motley Fool, Motley Fool CAPS.

Whether you're keeping an eye on silver with the iShares Silver Trust or are watching Japan with the iShares MSCI Japan Index Fund, it pays to watch. We can help you keep tabs on your companies with My Watchlist, our free, personalized stock tracking service. Click here to start now.