In yet another incremental step in the ever-shrinking world of investor fees, Charles Schwab on Tuesday said it has added 25 exchange-traded funds to its Schwab ETF OneSource commission-free ETF platform.

The additions boost the platform’s roster to 539 ETFs available commission-free to Schwab’s customers including individual investors, independent investment advisors using Schwab’s custodial services, and through Schwab retirement accounts that permit ETF trading. In aggregate, this lineup covers 83 Morningstar investment categories.

The 25 added products come from seven existing providers on the platform: 10 from Direxion; seven from JPMorgan; three from Global X; 2 from IQ MacKay (part of New York Life Investments); and one each from John Hancock, Pimco and State Street Global Advisors.

These new funds cover a range of asset classes including domestic and foreign equities, as well as various fixed-income strategies.

Both Schwab ETF OneSource and Fidelity Investments this year have significantly increased the number of commission-free ETFs on their respective brokerage platforms. As mentioned, Schwab’s latest expansion gives it 539 such products, while Fidelity offers 503 commission-free ETFs.

Vanguard’s brokerage platform offers commission-free trades on roughly 1,800 ETFs.