Originally published on swiftedge.uk . Swiftedge makes free browser tools for live Bitcoin and Ethereum order flow.

Cumulative volume delta, or CVD, is a running total of aggressive buying minus aggressive selling . It answers a simple question: since the start of the day, have traders who cross the spread been mostly buying or mostly selling? This guide explains how it is built, how to read it next to the order book, and what two and a half years of Bitcoin data say about what it can and cannot tell you.

From one trade to CVD

Every trade has two sides: a resting limit order (the maker ) and an order that crossed the spread to hit it (the taker, or aggressor ). If the taker was buying, the trade adds its size to delta ; if the taker was selling, it subtracts.…