"Short ladders are supposed to be done on very low volume, to simulate trading and price discovery without actually committing large positions (that would defeat the point), but that period highlighted saw some of the largest volume of the day. You're looking at something like 500,000-1,000,000 shares traded every five minutes without accounting for volatility halts freezing the action for 5 minutes at a time. As I watched this live it was really more like a million shares in 30 seconds and then halt, repeated about half a dozen times.
This person's chart is using a small time increment <5 minutes, and since halts last for 5 minutes, this gives a false impression of what was going on. Some bars with suspiciously little to no volume were the result of the stock being temporarily halted from trading.
So this wasn't a short ladder so much as a liquidation of a very large long position. 1/28 was the day when most brokers started banning buying shares, hence the obvious liquidity problem - few bidders to support the price.
P.S. Btw, the lack of liquidity to absorb a large long exist is perhaps one of the reasons why some hedge fund guys on the long side (looking at you, Chamath) have been pressuring brokers to open up trading as well as pitching new startup brokers over social media. The guys who were long at 10 bucks need to unload, and they need willing hands to hold their bags."
