New York CNN  — 

JPMorgan Chase’s investment bank has been hired to advise First Republic as the embattled regional bank tries to ease concerns about its financial condition, people familiar with the matter told CNN.

First Republic’s share price has plummeted 90% to record lows over the past month as investors took scrutinized lenders with a high amount of uninsured depositors — a response to the collapse of Silicon Valley Bank and Signature Bank earlier this month.

First Republic’s nosedive continued even after 11 of America’s biggest banks, including JPMorgan, Citigroup and Wells Fargo, provided First Republic with a $30 billion rescue last week. Despite that effort, both Moody’s and S&P Global Ratings downgraded First Republic’s credit ratings over the weekend.

Now, San Francisco-based First Republic has hired JPMorgan’s investment bank to help management explore its options, including potentially raising additional capital, the people familiar with the matter told CNN.

Both JPMorgan and First Republic declined to comment. News of JPMorgan’s hiring was previously reported by CNBC

First Republic shares rallied 22% in premarket trading Tuesday, rebounding from a 47% plunge on Monday.

Jim Herbert, First Republic’s founder and executive chairman, and CEO Mike Roffler last week expressed their “deep appreciation” to the big banks for their $30 billion lifeline.

“Their collective support strengthens our liquidity position, reflects the ongoing quality of our business, and is a vote of confidence for First Republic and the entire U.S. banking system,” the First Republic executives said in a statement last week.