(Photo: Bloomberg)

Six years after it first rolled out its commission-free ETF platform, Schwab is set to double the number of products on OneSource — to 503 — starting March 1. Plus, the lineup will include iShares ETFs for the first time, the firm said early Tuesday.

But the brokerage firm isn’t alone in making such an announcement. Fidelity also said Tuesday morning that it has struck a deal with iShares and will boost its commission-free lineup to over 500 ETFs by Feb. 28. This news comes six months after the fund firm rolled out two index funds with zero fees.

“For Schwab, the decision to expand the lineup came in response to demand from both advisors and retail investor clients,” said Kari Droller, vice president of third-party platforms for the Fidelity rival, in an interview Tuesday at the Inside ETFs conference being held near Miami. “We always pay attention to this and are working to build the whole package for advisors and retail clients.”

Schwab OneSource does not offer leveraged or inverse ETFs or exchange-traded notes. “The riskiest products are not included,” Droller said, adding that the new lineup will encompass 79 Morningstar categories, such as commodities.

As of Dec. 31, OneSource had $115 billion in assets, up 10% from a year ago. Flows in 2018 were nearly $23 billion and accounted for roughly half of Schwab’s total ETF flows.

“Flows are about 50/50 from advisor clients and retail investors,” Droller said. “The commission-free component [of OneSource] is as important to advisors as it is to investor clients.”

Fidelity says its total ETF assets under administration are about $380 billion and have grown roughly 80% over the past three years.

“When combined with the unprecedented Fidelity Zero Index Funds …, the announcement today further reinforces Fidelity’s relentless focus on providing investors with unparalleled value, simplicity and choice,” said Anthony Rochte, head of Fidelity Institutional’s investments & technology group, in a statement.

In other words, the privately held, Boston-based firm plans to keep up the pressure on rivals — a fact that’s not lost on Schwab.

From a competitive standpoint, “commission-free trading and low to no costs are really key components to Schwab’s business, and that’s is why we are doing this” lineup expansion, Droller said.

In addition to iShares, other ETF providers bringing more products to Schwab OneSource include Invesco, State Street Global Advisors’ SPDR and WisdomTree.

“BlackRock is proud to participate in Schwab’s expansion of the OneSource platform,” according to the iShares parent. “This is unequivocally good news for investors and advisors on the platform, and iShares.”

Aberdeen Standard Investments, ALPS Advisors, Direxion, Global X ETFs, John Hancock Investments, J.P. Morgan Asset Management and PIMCO also are adding more funds to Schwab’s commission-free lineup.

Schwab says that no-commission trades must be done online by investors or via their independent financial advisors. When going through one of Schwab’s brokers, orders have a $25 fee; phone-based orders cost $5.

Fidelity offers free commissions for online purchases of its own ETFs and select iShares ETFs in a brokerage account.

— Check out Fidelity Cuts Trading Prices, and Schwab Follows on ThinkAdvisor.