Momentum

Momentum is the speed and force behind a move. A price that rips 100 pips in an hour has strong momentum; one that crawls up 100 pips over a week has much less. Think of a sled: once it is flying downhill it tends to keep going, until the slope flattens and it starts to slow.

Traders measure it with indicators like rate of change, RSI and MACD. Watching momentum fade while price still inches higher is one of the classic early warnings that a trend is running out of steam.