The most valuable short position in the world, in FINRA's twice-monthly counts: a quarter of Tesla sold short at the 2019 low, and the two-year unwind into the S&P 500 inclusion.
Figures are the short interest as a percentage of shares outstanding, from FINRA data, 68 points between 12 Jan 2018 and 31 Dec 2020.
For much of 2018 and 2019 Tesla was, by dollar value, the largest short position in any single company anywhere. The FINRA figures show why: 18.26% of the company's shares outstanding were sold short at the start of 2018, and the position reached 25.11% on 31 May 2019, around the time the shares touched a multi-year low amid production problems and questions about the company's finances.
The August 2018 "funding secured" episode, when the chief executive said he was considering taking the company private, and the securities-fraud settlement that followed, sit inside this window; the position barely moved through it.
From late 2019 the share price rose more or less continuously, and the reported short position fell in step as positions were closed: by 31 Dec 2020, just before the company's inclusion in the S&P 500 index in December 2020, it stood at 6.40%. The five-for-one stock split of August 2020 changed the share count without changing the percentage, which is why the chart shows no step there.
Days to cover in this window peaked at 7.26 days on 30 Apr 2018, and stayed low throughout because the shares traded so heavily.
Full history and today's figure: Tesla, Inc..
US short interest data: FINRA (finra.org). FINRA® is a registered trademark of the Financial Industry Regulatory Authority, Inc. This site is not affiliated with or endorsed by FINRA or the SEC; displayed for personal reference, bulk redistribution is not permitted (see terms). The narrative describes what the published figures showed and widely reported public events around them; it is not a description of any company's prospects and is not investment advice.