Have you invested in an exchange traded fund? If so, you there is a high probability you have paid BlackRock (NYSE: BLK) some money in fees. But don't worry: You are not alone, and there is a way to get back some of those fees.

Why did someone invest in a Spider?
Let's take a step back. The world of ETF investing has exploded over the past decade, and BlackRock's iShares is the 800-pound gorilla in the space. ETFs trade like stocks, yet at the same time, they provide diversification benefits, low expenses, and are relatively tax efficient. Most ETFs aren't actively managed and as a result have low turnover and lower costs than actively managed mutual funds.

The first true ETF was issued in 1993 to track the Standard and Poor's S&P 500 index. This ETF trades under the ticker SPY and commonly referred to as "spiders."

ETFs generally track indices, but there are also ETFs that track bonds, commodities, and make leveraged bets. The Proshares UltraPro Short S&P500 (NYSE: SPXU) allows investors to take a triple-levered bet against the S&P (although, investor beware of these kinds of tools). You may have read stories around year end about superstar hedge fund manager John Paulson making a majority of his most recent $4 billion paycheck through a bet on gold; his largest holding is a commodity ETF, the SPDR Gold Trust (NYSE: GLD), which is issued by a division of State Street (NYSE: STT).

ETF explosion
It didn't take long for investors to grasp this unique instrument. As of March 31, there were more than 2,600 ETFs globally, up from less than 150 in 2000. These ETFs total more than $1.3 trillion and come from 142 different issuers. iShares simply dominates this market. iShares is the largest issuer with 461 of those ETFs and also has the largest amount of assets under management in its ETFs with $609 billion. This gives iShares a 43.5% market share as of March 31.

Recoup your fee
Now, how does this relate back to BlackRock, and more importantly, you recouping some of your ETF fees?

BlackRock purchased iShares in 2009. And, if you buy BlackRock, they will use some of that iShares fee income to pay you a 2.7% dividend.

BlackRock's purchase of Barclays Global Investors two years ago was part of BlackRock's strategy to take over the world -- or at least to become the largest asset manager in the world. And by largest, we mean larger than the Fed. BlackRock manages a staggering $3.65 trillion, which puts the U.S. Federal Reserve's $2.8 trillion balance sheet to shame.

The biggest gets bigger?
Well, the Fed has proved that it can grow, but BlackRock is not about to get stale, either. BlackRock's annual earnings-per-share growth rate over five years is 24%, and total net income has grown at a stunning 54% annual rate over the past five years. BlackRock has net margins of nearly 25%.

Can it keep growing?
However, a compelling story alone isn't always reason to buy a stock. Especially with financial services firms, paying a fair price is extremely important as well. In the case of BlackRock, there seems to be ample upside. For example, the average analyst target on the stock is $232 per share, 15% above the closing price of $200.67 last Friday.

Is it for you?
BlackRock is a way to invest in a financial stock without the hidden toxic asset worries of Bank of America (NYSE: BAC) and its peers. In November of last year, PNC Financial (NYSE: PNC) and Bank of America were kind enough to sell down some of their large stakes in the company and increase the float for everyone else. Also, Standard and Poor's added BlackRock to the S&P 500 on April 1, 2011, and it has since been included in many institutional portfolios. BlackRock is a way to profit on the booming theme of ETF investing and do it through the safety of a behemoth that is bigger, and arguably safer, than the Fed.

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Eric Bleeker owns no shares of the companies mentioned. Motley Fool newsletter services have recommended buying shares of BlackRock. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.