At any given moment there will be a ton of offers people have made to buy or sell at a given price out in the market (whether it's Coinbase, NYSE or whatever).

At any given moment there will be a ton of offers people have made to buy or sell at a given price out in the market (whether it's Coinbase, NYSE or whatever). See [0] for an example of how this "order book" is visualized. In the middle is where the actual transactions are happening. A fake sell wall is a giant offer to purchase at a price that is pretty far from the current market price. On that chart it would be visible as a large vertical uptick. As the price goes down and approaches the huge buy order, the trader cancels it and the wall disappears. On a traditional exchange this is technically possible, but it's illegal to intentionally manipulate the market by placing orders. People often complain that high-frequency traders put in these orders and cancel them immediately without having the intention to actually transact. 0: https://www.bitstamp.net/market/order_book/ https://www.bitstamp.net/market/order_book/