Order flow predicts how much, not which way

Most market content is sold on direction: will it go up or down. We went looking for that signal in second-by-second order-book data across six major coins — BTC, ETH, SOL, BNB, XRP and DOGE — and kept running into the same result.

Directional edge, tested out-of-sample, sits close to a coin flip. But a different quantity holds up well: how much the market is about to move.

What we measured

For each second we track eight order-book features: the resting walls on each side, how those walls grow or pull back, and executed buy/sell volume. From these we build a simple flow-intensity reading and ask a plain question: when flow spikes, what happens next?

The pattern

When walls thin out and flow surges, the following stretch tends to move harder — forward volatility rises meaningfully. When the book sits thick and quiet, the next stretch tends to stay calm. The link is to magnitude, not to a particular direction: an up-surge and a down-surge look almost the same on the way in.

Why it matters

It reframes what the tape is good for. Order flow is a decent volatility instrument — useful for sizing, timing and risk — and a poor compass. We publish results that survive walk-forward testing against a plain buy-and-hold benchmark, and we say clearly where the edge stops.