I also saw that 100K shares at $2.530058 time 15:55:22PM go through. Could be a market maker covering
That was someone that has been selling all day and completed the order. If they don't finish, they post an after market t-trade and continue the next day, if they finish during the day, they post when it is done. The size, 6 decimal places, and 15c under the bid gives it away.