Longtime hedge fund manager Bill Ackman on Wednesday advised President Donald Trump to shut down the U.S. for one month in an effort to contain the novel coronavirus and said financial markets would rally in response to such decisive action.

Ackman, who founded Pershing Square Capital Management, called on the president to both close the nation's borders as well as offer Americans a one-month rent, interest and tax holiday to help offset an expected deceleration in U.S. GDP growth.

"Mr. President, the only answer is to shut down the country for the next 30 days and close the borders. Tell all Americans that you are putting us on an extended Spring Break at home with family," Ackman wrote on Twitter.

"The moment you send everyone home for Spring Break and close the borders, the infection rate will plummet, the stock market will soar, and the clouds will lift," he added.

ackman tweet

Ackman later in the day spoke to CNBC's Scott Wapner and detailed his thoughts further.

"Beginning in late January I was getting increasingly bearish and I woke up with a nightmare. And my nightmare was you have this virus that replicates and infects incredibly rapidly," he said.

Ackman revealed he went into lockdown almost a month ago to save the life of his father, who is immuno-compromised.

"You look at the beaches at Fort Lauderdale: Unfortunately, they're packed with 18-to-22-year-olds having the time of their lives, spreading the virus," he said.

"They're probably OK, most of them ... but when they go home to their parents, or they go home to their loved one, or to their friend who just had breast cancer surgery and is immune-compromised: They're going to kill that person," Ackman said.

"Everyone feels, you know, '99% chance I'll be OK!'" he continued. "But it's not you: It's the person you give it to. I am not going to kill my father, OK?"

He also said he urged the companies he's invested in to halt their buyback programs and extend their credit lines because "hell is coming."