Reading the Order Book Before a CPI Print

Depth is not a constant. In the ten minutes before a scheduled macro release, resting size on both sides of the book thins out, and it thins out fastest at the levels you are most likely to trade into.

What Thinning Looks Like

On a normal afternoon the top ten levels of BTC perps hold enough to absorb a mid-size market order without moving mid more than a tick or two. Twelve minutes before a CPI print, the same ten levels hold a fraction of that.

A stop-market order in that window is a request to be filled at whatever price still exists. On a challenge account, that is how a planned 1% risk becomes a 4% day.

What To Do Instead

1. Cut size before the window rather than widening stops
2. Use resting limit orders so you are the liquidity, not the taker
3. Check the news calendar in the trade panel; the window is marked