When the line on the chart goes down that means the peso has strengthened against the dollar.
The currency is up by 2.2% at 19.5562 per dollar around 9:11 a.m. ET.
"The peso has fallen a lot mainly because of the fear of what will happen with [the North American Free Trade Agreement]. I believe that if we and the Mexicans make a very sensible trade agreement, the Mexican peso will recover quite a lot," he told CNBC on Friday.
The peso saw a tumultuous autumn and ended up being one of the big market casualties of the 2016 election. It crashed by about 20% after President Donald Trump won the election.
However, it has been on the uptick in 2017. In mid-February, it pushed to the strongest level against the greenback since the day after Trump's election after US Secretary of State Rex Tillerson met with Mexican officials.
Back during his confirmation hearing, Ross said that NAFTA would be an early priority for his department. He said he was "pro-trade," but only as long as it is "sensible trade."