This could indicate that the order is not genuine, especially where a distinctive pattern of such orders is observed. At the time the bid (or offer) was made, the Trading Member or Trading Representative did not intend to buy (or sell), but intended that the bid (or offer) would not trade and would be withdrawn eventually. Sometimes, such orders are entered to induce buyers (or sellers) into the market to facilitate the filling of an order on the other side of the market.
Added on 3 June 20193 June 2019.