Iceberg lettuce get married. We cantelope.
Psychology isn’t the only field that uses the iceberg analogy. An iceberg order is one super-big order (we’re talking securities here) that’s been divided into multiple, smaller limit orders (the orders where you pick the highest price you’re willing to pay before the order will be executed).
Iceberg orders get their name because the large order broken up into smaller orders hides the order quantity. You can see “just the tip of the iceberg” rather than the entire order.
Why would someone want to hide a large order? Investors making huge orders...brokerages and other financial institutions...don’t want to give away their information to the market.
It’s like playing poker, and they are only showing one card rather than their whole hand. If they did show their whole hand, other investors paying attention could set off a chain reaction, affecting the supply, demand, and price of a stock. Which makes sense, since iceberg orders are made up of limit orders, which are orders holding out for a better deal.