There has been a lot of talk in the world of exchange-traded funds that giants like Vanguard Group, BlackRock‘s iShares and Charles Schwab are headed in the direction of trading without any management fee at all. We’re not there yet, but Vanguard Group is making a major move related to ETF fees that no other firm has yet made. Starting in August, investors using Vanguard’s online brokerage platform will be able to trade all ETFs on a commission-free basis, including ETFs from rivals iShares, Schwab and State Street Global Advisors.

Investors who use the online Vanguard platform can already trade its ETFs for free and have been able to do that for a decade. Other brokerage platforms have signed exclusive deals with specific ETF providers to offer commission-free trades as competition has increased, such as Fidelity Investments’ tie-up with iShares, but no online platform has gone near this Vanguard move, which includes access to more than 100 ETF providers and roughly 1,800 ETFs of the roughly 2,000 in the market.

Yet there is one big exception: Vanguard will not offer commission-free access to leveraged or inverse ETFs. Vanguard said it was excluding the leveraged and inverse ETFS due to “their speculative nature runs counter to our investors’ focus on long-term success.”

“This is a significant move by Vanguard,” said Todd Rosenbluth, director of ETF and mutual fund research at CFRA. “Other brokerage firms, such as Schwab or TD Ameritrade, provide commission-free trades on a subset of ETFs, with the asset managers supplementing the cost savings.”

Rosenbluth said the idea that Vanguard brokerage investors will be able to trade SSGA’s SPDR S&P 500 (SPY) and iShares iBoxx High Yield (HYG) commission-free is not something CFRA expects other brokerage firms to follow, because it would require them to forgo their existing exclusive relationships.

“The ETF price war has been escalating and spreading to all corners. This is the latest salvo by Vanguard, one of the low-cost leaders in the ETF space, aimed at attracting new clients and then offering them other services, where they can make more money. It is a big development in the ETF price war,” said Neena Mishra, director of ETF research at Zacks Investment Research.

Mishra does believe competitors will make moves in response and soon. But Vanguard also has an advantage in that it is an asset manager first and brokerage business second. Its business model relies less on brokerage revenue than stickiness of fund assets.

“Vanguard is more an asset manager that offers a smaller platform for trades to occur, whereas other firms profit more from the assets on and the trades via a brokerage platform. By moving to commission free for all, a brokerage firm forgoes some revenue in exchange for stickier assets,” Rosenbluth said.

E-Trade Financial offers commission-free trading on more than 250 ETFs. TD Ameritrade offers commission-free access to more than 300 ETFs.

Both Fidelity and Schwab have scale benefits of being both an asset manager and a brokerage platform for trading ETFs, Rosenbluth noted, but he could not speculate on how they would respond.

“Schwab and Fidelity are more likely to come up with similar moves,” Mishra said. “Both already have commission-free trading for their own ETFs as well as some other issuers.”

Charles Schwab was an early leader with 200-plus commission free ETFs, including its own ETFs and many ETFs from other major providers. Fidelity has 95 (its own and many iShares ETFs). “Both are likely to expand these platforms soon,” Mishra said.

Vanguard is making a greater play for the online brokerage business and noted in their release that it has made “considerable enhancements” to its brokerage platform over the past several years.

While the move is a win for investors, it is also important for investors not to place all the emphasis on trading fees, especially as the fee wars at the level of the individual ETF and trading platform will continue. Similar ETFs in asset class or theme still vary in stock selection, liquidity and trading costs, among other factors. But it is hard to argue with what investors are telling these ETF companies.

According to a recent annual Schwab ETF survey, 45 percent of millennial and 39 percent of Gen X investors surveyed say commission-free ETFs are most important and they’d move their account to a firm that offered commission-free.

“CFRA thinks investors need to go beyond what ETFs trade commission-free on certain platforms, but we acknowledge this is a priority for many,” Rosenbluth said.

There is also a risk it becomes too easy and cheap to trade ETFs, something index fund creator and Vanguard founder Jack Bogle has remarked on repeatedly. “Recent fund flows clearly show that investors are becoming more cost conscious and moving their dollars to the cheapest ETFs. And while there is no doubt that investors are big winners as the fee war escalates, the downside is that the ease of trading and low transaction costs are also leading investors to trade more often, particularly in volatile markets,” Mishra said.