For any ZEC amount, how many shielding transactions into Orchard or Ironwood have ever moved at least that much. Ironwood counts every inflow since it activated, migrations from Orchard included: a coin that arrived that way is a plausible source for a later Ironwood deshield.
This is your anonymity set when deshielding — an observer cannot determine which of these shielding events is the source of your withdrawal. Larger amounts have smaller anonymity sets. This is a worst-case lower bound; actual anonymity is higher due to within-pool mixing.
Data is cumulative all-time and only grows. The time range filter does not apply to this chart.
This chart is plotted against ZEC amount, not date — each point is a shielding size.
🔗 permalink ⇆ compareFor any amount, this counts how many shielding transactions into Orchard or Ironwood have ever moved at least that much. That count is your cover: when you deshield, an observer knows the amount, and your transaction is indistinguishable only from the other shields that could plausibly have produced it.
Bigger is better, and the curve falls fast. Small, round amounts have thousands of companions. Large or unusual amounts have very few, and an amount with a handful of possible sources is not private in any useful sense — the maths held, and the crowd was too small to hide in.
This is why amount choice matters: shielding 1,000 ZEC and later deshielding exactly 1,000 ZEC links the two ends whatever the cryptography does. The round-trips page shows people doing precisely that.