Robinhood's shares have plunged more than 80% since its IPO.
The Federal Reserve doesn't have the tools on its own to fix supply problems, he said.
Tens of thousands of Vanguard clients claim the company caused them to get hit with higher tax bills this year.
Hiring will be across all job functions, Fidelity said.
Trading activity on Robinhood has declined, and its new offerings are not filling the revenue gaps.
The move ends the companies long pause on international expansion.
Customers placed 6.58 million daily average trades in the first quarter, a decline of 22% from the year-ago.
Equity funds led the way, with a $76 billion haul, while bond funds saw $7.5 billion.
Those with at least $100,000 in advised assets get unlimited access to Vanguard advisory services.
The company has begun adding support for traditional IRA and Roth IRA retirement accounts.