One of the sectors that has suffered the most in the coronavirus pandemic is commercial real estate. Bank reports suggest that tens of billions of dollars of mortgage-backed securities in the commercial sector have suffered repayment issues. Further, the share prices of many commercial real estate investment trusts have collapsed in value. Investors who have bet against the sector have made significant profits. Carl Icahn (Trades, Portfolio) announced publicly that he was betting against malls and physical retail towards the end of last year. Since then, he has reportedly earned $1.3 billion betting against the mall-heavy CMBX 6 index.