The exchange-traded fund market has swelled to a multitrillion-dollar industry. One gigantic provider not only stands out among the rest but also recently gobbled up several billion dollars' worth of additional ETF assets. Let's take a closer look at the recent deal and what it means for investors.

Goliath flexing his muscles
Earlier this month, BlackRock (BLK -0.46%) closed an ETF acquisition deal with Credit Suisse (CS). The world's largest asset manager agreed to take nearly $18 billion worth of the Swiss bank's ETF fund assets. As a result, BlackRock gained all 58 of Credit Suisse's ETFs, which have been absorbed and rebranded under BlackRock's popular iShares platform.

The acquisition not only grants BlackRock clients access to a large and diverse European ETF offering, but also bolsters the asset manager's position as the market leader in Europe's ETF industry. Meanwhile, the deal dovetails with Credit Suisse's goal of streamlining its business operations in light of more rigorous regulatory requirements.

This acquisition comes after a deal was secured in March that effectively extended a three-year-old contract between BlackRock and Fidelity. The partnership grants Fidelity's millions of individual and institutional customers broader access to iShares ETFs.

Good news for ETF investors too
Even excluding the multibillion-dollar tally of Swiss-based funds, BlackRock's empire is colossal. Its iShares ETFs overwhelmingly dominate the market, holding about 40% market share. With roughly 23% share of the ETF market, State Street's (STT -0.80%) SPDR ETF business comes in second place. Vanguard rounds out the top three. These top ETF managers account for roughly 84% of the industry assets.

Exchange-traded products such as these have grown globally by about 30% each year during the past decade. As more money pours into ETFs, economies of scale kick in, which knocks down expense ratios. And as competition heats up, providers scramble for your dollars and open up more commission-free ETF platforms. For example, Charles Schwab (SCHW -0.65%) launched commission-free ETF trading in November 2009, and back in February, it expanded its commission-free offerings under its new OneSource program to offer more than 100 commission-free ETFs. Even though the ETFs available on the OneSource platform don't make up a huge portion of the overall ETF market -- the assets managed by those 105 ETFs make up about 3.5% of total ETF assets under management across the industry, according to Marketwatch -- the platform has been successful in attracting roughly $17 billion in assets under management since its launch date.

Foolish bottom line
It remains to be seen if BlackRock and Credit Suisse shareholders will win or lose from the deal. But an increased number of choices give ETF investors more opportunities and latitude when crafting their portfolios. And as competition heats up and access to even more ETFs becomes available, it drives the costs of ownership down, making ETF investors the big winners.

It's now possible to invest in some first-rate ETFs for practically nothing. Luckily for you, we've combed through the vast ETF universe and hand-selected three great ones. To learn more about a few ETFs that have great promise for delivering profits to shareholders, check out The Motley Fool's special free report "3 ETFs Set to Soar." Just click here to access it now.

Editor's note: A previous version of this article incorrectly identified the initial commission-free ETF platform Schwab introduced in November 2009 as OneSource, which was actually a later-introduced program in February 2013, and used an out-of-date figure for OneSource assets under management. The Fool and the author regret the error.