"I write to inquire how your bank is monitoring and managing the economic threat and potential risk to your bank related to the spread of coronavirus in China and around the world," each copy of the letter reads.
"As a globally systemic important bank, your institution and the customers it serves could be impacted," the letters say, "either directly through exposures to areas where the virus has spread or indirectly through a change in market conditions caused by disruptions in supply chains, a drop in tourism or travel, or numerous other factors that could cause a slowdown in economic growth."
The Massachusetts senator sent the letters less than a week before Super Tuesday and just one day before South Carolina's primary election. Once seen as a leader in the race to defeat President Donald Trump in 2020, Warren's campaign has struggled with fundraising in recent months and fallen behind other candidates in the polls.
But the global spread of the coronavirus has injected a new element of uncertainty into the political mix. Market fears about the impact of the virus, which has killed more than 2,800 people and infected tens of thousands more, have sent stocks in spiraling downward.
Trump's approval ratings, which ticked up in the wake of his impeachment acquittal by the GOP-led Senate earlier this month, have sunk back down, according to some polls, as his handling of the health crisis comes under scrutiny.
The White House has taken measures, such as imposing travel restrictions and quarantines, to contain the virus' potential growth in the U.S. Trump also put Vice President Mike Pence in charge of the U.S. response to the coronavirus.
Warren has long been involved in efforts to regulate and increase oversight of major banks and corporations. As a member of the Senate Banking Committee, she gained fame for her harsh grilling of banking regulators in the wake of the Great Recession.