Washington (CNN) Senate Intelligence Chairman Richard Burr, a North Carolina Republican, has asked the Senate Ethics Committee to review his sales of hundreds of thousands of dollars of stocks last month ahead of the economic downturn sparked by the coronavirus pandemic, but he's not the only senator facing scrutiny over stock sales.

Georgia GOP Sen. Kelly Loeffler and others are also facing questions about why they were selling stocks last month, before the stock market took a nosedive as the outbreak spread across the US and the Dow Jones Industrial Average lost roughly 30% of its value.

The sales have sparked calls for Burr's resignation and attacks from political opponents from senators up for reelection in 2020.

There's no evidence that any of the sales, including Burr's, broke any laws or ran afoul of Senate rules. But the sales have come under fire after senators received closed-door briefings about the virus over the past several weeks — before the market began trending downward.

Loeffler and her husband sold 27 stocks between January 24 and February 14 at a value of $1.28 million and $3.1 million, according to Senate financial disclosure records. They also purchased three stocks for between $450,000 to $1 million, including shares in Citrix, a software company used for teleconferencing that's one of the few that's gained value amid the coronavirus outbreak. Citrix's stock was $122.03 on February 14, the day it was purchased, and closed at $125.31 on Thursday.

The amounts are not exact because lawmakers only have to report the sales as a range of values.

The stocks that were sold have lost an average value of approximately 32% — losses Loeffler and her husband avoided — from the date they were sold to their closing price on Thursday, according to a CNN analysis.

Loeffler has not filed a financial disclosure form yet, but she's reportedly one of the wealthiest senators . Her husband, Jeffrey Sprecher, has been the chairman of the New York Stock Exchange since 2016.

Loeffler denied having any knowledge of the stock sales, saying the decisions were made by a third-party adviser and she did not learn of the sales until later.

"I am not involved in the decisions around buying and selling," she said in a Fox News interview Friday . "There are a range of different decisions made every day that I am not involved in. ... I have adhered to the letter and the spirit of these rules."

Asked Friday whether she'd ask the Ethics Committee to investigate, Loeffler said she would be "happy to answer any questions."

"There was no corruption -- this is called transparency," she said.

Loeffler's political opponents went on the attack. Loeffler is facing a challenge from fellow Republican, Rep. Doug Collins of Georgia, in her Senate race and he accused her of profiting off of the coronavirus pandemic.

"People are losing their jobs, their businesses, their savings and even their lives and the thought of a Senator profiting off of the crisis is sickening," Collins said in a statement. "As public servants we are supposed to put the people we represent above ourselves. That's what the President is doing, his team, Congress. What I thought all of us were doing."

Congress passed the Stock Act in 2012 that made it illegal for lawmakers to use non-public information for financial benefit. There's nothing, however, that suggests the stock selling from senators was illegal, based on non-public information, or that any Senate rules were broken.

Watchdog groups have called for Securities and Exchange Commission investigations into both Loeffler and Burr. No one is under as much scrutiny as Burr, as there have been calls for the North Carolina Republican to resign coming both from Democrats and Fox News host Tucker Carlson. Even Sen. Thom Tillis, Burr's fellow North Carolina Republican, said on Twitter Friday that Burr "owes North Carolinians an explanation" and that the ethics review was appropriate.

Burr sold off shares worth between $628,000 and $1.7 million in 33 transactions on February 13. It's unknown how much profit Burr made on the stocks, as lawmakers are only required to report the total value of the sale.

Others are also facing criticism, even those who traded relatively smaller amounts or sold fewer stocks than Burr and Loeffler.

Sen. David Perdue, a Georgia Republican, sold 42 stocks in February for between $98,000 and $770,000, for instance, but he also purchased 40 stocks worth between $138,000 and $845,000 last month. Perdue regularly listed several dozen trades in each monthly filing, according to Senate records.

Jon Ossoff, a Georgia Democrat running for Senate against Perdue, attacked the sales, accusing him of "profiteering on an impending pandemic."

Ossoff's campaign pointed to Perdue's sale of Caesars Entertainment, which has been hit particularly hard by the restrictions on travel, and the purchase of stock in Pfizer, a pharmaceutical company. But Perdue also bought stock Delta Airlines, another stock that has lost more than half its value in the past month with travel restrictions around the world.

"Since coming to the US Senate, Sen. Perdue has always had an outside advisor managing his investments and he goes above and beyond to fully comply with the law," said a Perdue spokeswoman. "The Senator is not involved in any day-to-day investment decisions. Like most Americans, using an outside advisor is how many people manage their retirements and 401ks."

Other sales were reported last month by Sens. Dianne Feinstein, a California Democrat, and Jim Inhofe, an Oklahoma Republican.

President Donald Trump was asked about the sales made by Burr and Loeffler at a press briefing Friday, but he chose to focus on Feinstein instead, asking a reporter why she wasn't being mentioned.

But Feinstein herself did not sell any stock, as it was her husband who sold between $1.5 million and $6 million in stock of Allogene Therapeutics, a biotech company, in January and February. Feinstein said on Twitter she has no involvement in her husband's financial decisions.

"I have no input into his decisions. My husband in January and February sold shares of a cancer therapy company. This company is unrelated to any work on the coronavirus and the sale was unrelated to the situation," she tweeted

Inhofe sold five stocks, worth between $180,000 and $400,000, in January, and another for $50,000-$100,000 in February. But he said in a statement he had no involvement in his investment decisions.

"In December 2018, shortly after becoming chairman of the Senate Armed Services Committee, I instructed my financial advisor to move me out of all stocks and into mutual funds to avoid any appearance of controversy," he said in a statement Friday. "My advisor has been doing so faithfully since that time and I am not aware of or consulted about any transactions."