If you can see the full list of buy and sell bids over all...

If you can see the full list of buy and sell bids over all prices the pattern is easy to spot since the timing gives them away in addition to the periodic nature of the placements. As H said, it is generally designed to cap the price and attract additional sellers at an otherwise lower price. The other trick to watch out for is the pattern of stacked buy bids. These are often placed in a row below the market and filled with a rush when the coast is clear ie the higher buy bid is filled. This occurs when a "seller" fulfills their own buy order ensuring they do not lose stock but serves to reduce the price below the market price that would otherwise be operating. They don't supply the shares to the higher bid as they would lose their stock to a real buyer. To detect these movements you have to be quick. In a sense it engenders confidence as you know there are some desperate to add to their holdings but is also irritating to many when used repeatedly.