Schwab is adding 18 more ETFs to Schwab ETF OneSource starting next month, Schwab announced Monday.

Schwab ETF OneSource offers investors commission-free ETFs. With the addition, Schwab will offer 198 ETFs covering 64 Morningstar categories with no online trade commissions.

There are no enrollment requirements or early redemption fees, which differentiates it from most other commission-free ETF programs, Schwab says.

OneSource has $38 billion in assets under management as of the end of last year. Flows into ETFs in the program were more than $10 billion in 2014, representing 43 percent of the total ETF flows at Schwab, the firm says.

The platform includes funds from 13 leading providers and provides access to momentum ETFs, single-country ETFs, a Bullish Dollar ETF and non-traditional Bond ETFs, among others.

A complete list is available on the Schwab website.

“The traction we’ve been able to achieve in a relatively short period speaks volumes about the importance of cost when it comes to selecting an ETF, and we are excited to be able to continue to expand this program to meet investor demand,” says Heather Fischer, vice president of ETF Platform Management at Charles Schwab.