Ms Loeffler, who is fighting to retain her Georgia seat, is married to the chairman of the New York Stock Exchange, Jeffrey Sprecher.
She is reportedly the wealthiest member of congress with a fortune estimated at between $800m and $1bn, according to Forbes.
She was appointed to the senate seat in December 2019 by Georgia governor Brian Kemp after Johnny Isakson resigned for health reasons.
Ms Loeffler finished second in the election last month and now faces a January run-off against Raphael Warnock.
"It's so important to have Senator Loeffler in the Senate, especially right now. What we need more than ever is a business mind," said former deputy director of the Georgia Republican Party Janelle King,
"We need someone who understands not just how to write paychecks and sign paychecks but how it feels like waiting on that paycheck.”
Ms Loeffler and her husband were investigated for insider trading after making investment moves on 24 January, the same day she received a pandemic intelligence briefing.
She was eventually cleared by Donald Trump’s Department of Justice and the Republican-led Senate Ethics Committee.
"She is worth 500 million dollars. She's is the wealthiest United States senator. She is running against a man who grew up in the projects,” said Twitter user Jason Patterson.
Ms Loeffler’s GOP colleague David Perdue is also involved in a tight run-off race with Democrat Jon Osoff.