A spike is a non-market quote, which is a sudden price movement that does not reflect real market activity. While it may look like a normal price change, it is actually caused by a technical error.
This is how a spike appears on the chart:
The signs of a non-market quote (spike) include:
A significant price change within a few seconds
The price quickly returning to its original level
The absence of any notable news or market events
Since these prices are not genuine market quotes, any trades executed at spike prices are canceled, and the spike is removed from the chart.