It could be the case that the shorter also has a substantial...

It could be the case that the shorter also has a substantial long position with both positions within their group netting to less than 5%. As far as I am aware long and short positions held within a s/s reporting group are not required to be aggregated - a severe weakness in market information if the case. The 4.5m shorted is upwards of $115m. This is either majority one substantial player or a group of substantial players playing in unison. The amount of money involved could suggest GS, MS, Citi etc. and quite possibly linked to the party/ies carrying out the algo trading. MS seems to have a clear big involvement in the ASX. One could also question whether any involvement by lending or otherwise of BNY who run the US OTC book. In any case, looks strategy driven and operated by algos. The shorters did almost nothing at the FDA spike. A Tesla action would do nicely.