If the seller had 5000 shares, they may have sold the 4100 previous shares at .069 and then whacked the bid for the remaining 900 at .0555. (Both sells would still be stupid in my opinion as well)
You're right gobsmacked. Could have been an internal MM trade to blunt the rising share price.
Unfortunately, there's no way to tell the difference between real retail and artificial internal MM trades.
They show up looking the same on the last sale reports.
It's my belief that there should be a way to distinguish between the two.
There's a MM just got busted for making 46,000 trades for the purpose of deceiving the market. They were fined and "admitted no wrong doing." Bunch of fraudulent turds.