A scam wick is when individuals intentionally trade at a price far out of the current trading range in an attempt to trigger people's stop losses, thus causing a cascade of buys/sells that push the price in the direction they want it to move.

For example, say ETH is trading at $200, and a lot people are shorting ETH because they think it's going to go down soon. A whale who wants to capitalize on that can look at the list of open orders and see there are a ton of stop losses at $220. If those are stop losses are triggered it will cause a flood of market buys, thus forcing the price upwards. So they open a limit order at $225, and get someone else to do a limit sell at $225. This triggers all the stop losses and causes the price of ETH to skyrocket higher.

It's called a scam wick, because on a candle chart, it may show a short body, with an extremely long wick.

INSERT IMAGE OF A SCAM WICK