Charles Schwab on Monday said it has added 15 exchange-traded funds to Schwab ETF OneSource, its commission-free ETF investing platform.

The new funds, which were made available to Schwab clients on Thursday, are divvied up across nine of the 16 existing fund providers on its platform, giving ETF OneSource 245 funds covering 69 Morningstar categories.

The platform had $84 billion in assets as of May 31, which Schwab says marked a 22 percent increase during the first five months of the year.

ETF OneSource offers commission-free online trading to individual investors at Schwab, to roughly 7,000 independent investment advisors who use Schwab’s custodial services and through Schwab retirement accounts that permit trading of ETFs.