Elon Musk triggered a $1.2B dollar short-squeeze on Bitcoin

How do we know how many shorts and at what price?

Wouldn't you have to check every bitcoin exchange? There is no central trading authority like the Dow or Nasdaq.

You can find aggregate liquidation data for Bitcoin futures and perpetual swaps in bybt.com

This is not a short squeeze. This is over leveraged short speculative positions getting liquidated.

The only evidence of short positions given is behind a paywall...

The article in OP mentions a Twitter account that gives these infos on their website: bybt_com