I've done some analysis of the havelock order book, and that sell wall is the same bot that bounces a couple of hundred shares back and forth between bid and ask.
Anyone planning on buying/selling on Havelock should also know you can manipulate that bot pretty easily and close the spread down to 3-5% since it will over/under bid you so it can be the market maker. Buy side seems to update its order every minute, ask side reacts to changes in the order book pretty quickly.
For example, the current bid is 0.12, but you could probably sell into the bot at around 0.125 -.128.