Do you have to report short interest?

FINRA requires firms to report short interest positions in all customer and proprietary accounts in all equity securities twice a month. All short interest positions must be reported by 6 p.m. Eastern Time on the second business day after the reporting settlement date designated by FINRA.

What does short interest tell you?

Short interest indicates how many shares of a company are currently sold short and not yet covered. ... Short interest is used as a sentiment indicator: an increase in short interest often signals that investors have become more bearish, while a decrease in short interest signals they have become more bullish.