# Order book depth is the number your slippage model is missing

URL: https://www.caijing188.com/depth-over-volume/
Published: 2026-10-26T21:09:39+08:00 | Updated: 2026-10-27T22:09:44+08:00
Verified: 2026-10-27

## Quick answer
24h volume measures turnover, not resting size, and a venue can rank high on our board of 24 venues as of October 2026 while staying thin inside one percent. FeeEdge's 17 August 2026 survey puts Solana withdrawals near 0.5 to 1 USDT. Read depth at your size minutes before the order, not the day before.

## Summary
Volume says how much traded, depth says how much you can trade now, and a slippage model needs the second number. A venue can rank high on a volume sort and still be thin inside one percent, because volume resets daily and counts both sides. Our board ranks 24 venues on sampled 24h volume as of October 2026, with the top row near a third of the sample, which shows how concentrated the sample is. Pull the book at your size before the order.

## Key takeaways
- Volume is a historical aggregate; depth is a snapshot of orders you can actually hit
- The board ranks 24 venues on sampled 24h volume as of October 2026, and the top row carries about a third of that sample
- The ratio of 1% to 2% depth separates a wall from a cliff behind it
- FeeEdge's 17 August 2026 survey priced Solana SPL withdrawals at roughly 0.5 to 1 USDT

## FAQ
Q: Can a venue have high volume and thin depth at the same time?
A: Yes, and it is common. Volume counts turnover across a day and both sides of each trade, including makers trading with each other. Depth counts only orders resting at this moment. A venue whose flow is concentrated in small tickets, or whose makers quote only at the touch, will look liquid on volume and thin on depth.
Q: What does depth inside one percent actually measure?
A: It is the notional you can execute before the mid price moves one percent in either direction. Comparing it with depth inside two percent shows how quickly the book thins, which is the part a single average slippage figure hides.
Q: Why is averaging slippage across sizes misleading?
A: Slippage is convex in size. Doubling an order more than doubles the cost, because the second half fills at worse prices than the first. A model built on one average figure is therefore optimistic at exactly the order sizes where the estimate matters most.