Tesla shares have gained a cumulative 649 percent year to date, which means short sellers have had a terrible year.

An analysis by financial analysis firm S3 Partners showed that Tesla shorts have lost $35 billion year-to-date. However, 2020 is not over yet.

"There's nothing that compares to it that I can remember," S3 Partners told CNN.

— S3 Partners (@S3Partners) December 9, 2020

How bad are Tesla's short losses? According to CNN, the US airline industry has a total loss of $24.2 billion for the first nine months of 2020. However, the Tesla shorts actually lost more than that.

Keep in mind that 2020 is the most difficult year in the history of the US airline industry and the worst year ever for the industry in terms of losses.

Just last month, Tesla short-sellers lost $8.5 billion, more than the $6.7 billion Tesla shorts lost in the 11 years between 2008, when it first reported results, and 2019.

Jim Chanos, president of Kynikos Associates, recently shared his thoughts on Tesla at media organization conferences: " however you might want to dream about autonomous taxis, spaceflight, tunnels underground, whatever - they are a car company, and they are an unprofitable car company. "

CleanTechnica editor-in-chief Johnna Crider believes Chanos made several mistakes. the first glaring mistake Chanos made was confusing SpaceX with Tesla.

The second mistake is that he confused The Boring Company, the transportation tunnel construction service provider founded by Musk, with Tesla.

His third mistake was to assume that Tesla is not profitable, when in fact the company has been profitable for five consecutive quarters and has been included in the S&P 500.

His fourth mistake was refusing to consider Tesla as a technology company, which he had previously commented on.

Early last month, S3 Partners' data showed that short sellers in Chinese electric vehicle (EV) maker Nio (NYSE: NIO) lost $155 million on November 3, bringing their cumulative losses this year to $2.66 billion.

As of November 3, when Nio surged by 6.54 percent, Nio's short interest stood at $2.35 billion with 76.75 million shares shorted, accounting for 7.14 percent of Nio's floating shares.

That was higher than the low levels of the recent past but was down sharply from that of December last year when 224 million shares were shorted, accounting for 25.15 percent of floating shares.