Iceberg order
An iceberg order is a large limit order that shows only a small part of its size in the order book and refills that part each time it is traded.
The book might show 5 units at a price while 50 are really waiting. The sign is trades printing at the same price again and again while the shown size keeps coming back. Many stock exchanges and some crypto exchanges offer iceberg (or reserve) orders; check whether yours does.
Learn more: the order book: how a price is made.