What does "short positions exceed float" mean?

External question — Personal Finance Stack Exchange Author: TJNI4fmgOSiB2yFX Original post: https://money.stackexchange.com/questions/136776 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. From the 2/18 GameStop hearing: Rep. Andy Barr: (02:01:32) [...] But Melvin lost $6 billion in 20 trading days. Let me ask you about your risk management. Did your short positions exceed float? What exactly does "Did your short positions exceed float" mean here?