What is a large trade in order flow?

A large trade is a single execution big enough to be somebody's decision rather than the tail of a stream of small orders. A hundred small trades and one large one can add up to the same volume, and they are not the same event: one participant acting at size says more about intent than a crowd drifting in the same direction.

What it looks like on the chart

On the one-hour BTCUSDT heatmap above, each Big Trades circle marks one trade above the size threshold, placed at the price it executed and sized by its value — every one here in the selling colour, a seller hitting the bid. Near the 18:02 high, around 76,420, trades of +1298.1k and +736.7k printed as price topped. During the decline into 18:39–18:46, a cluster printed near 76,150–76,200: +618.8k, +797.9k, +660.3k, +474.1k and +494.9k — several large sellers acting at the same level as price slid into it.

How traders read it

• One decision, not an accumulation. A large trade is evidence someone acted at size at that price — not evidence they were right.
• Where it lands is as important as its size: a large trade into a bright band of resting liquidity met size; one in thin liquidity had the level to itself.
• Beside a sweep. A sweep is size pushed through several levels in one motion; a large trade is one fill. Seeing both tells a lone block from a push.
• Clusters of large trades at one price are several participants deciding at the same level.

On TapeHawk

The Big Trades indicator draws a circle on the heatmap wherever one trade printed above the size you set, in the buying colour when a buyer paid the offer and the selling colour when a seller hit the bid. A trade is a fill, not an order: an order that ate four price levels arrives as several fills, so the order behind a circle can be larger than the circle. The size is an absolute amount, so one setting does not fit every symbol. It is drawn on heatmap panels of the symbols TapeHawk records and reaches back 24 hours.