Definition. The total balance held by exchanges and the part of it that is exposed to potential attacks by quantum computers. Supply is exposed when the public key that controls it is already visible on-chain: it sits in a P2PK or Taproot output, or on an address that has already spent an output. Two series: the total and the exposed balance.

Technical. Each data point reflects the balance at the end of the month. The metric is refreshed only once per month. Available per exchange or aggregated across exchanges. An exchange's series starts in the first month it holds a balance. Exchange holdings are identified with Glassnode's entity clustering, so the history can revise when the clustering is updated.