CEL Solicitors states it has traced more than 5,500 BTC that it believes belong to former users of Intersango, an early Bitcoin exchange that disappeared more than a decade ago. ^[1] One former UK customer recovered 61 BTC from the exchange's remains, settling the case on May 28 after instructing CEL on Jan. 20. ^[2] Bitcoin's pseudonymous nature makes it challenging to analyze user-level activity because a single user may control multiple identifiers known as addresses. ^[3] The authors propose a method for refining heuristic-obtained clusters by grounding the clustering on contrastive embeddings yielded by graph neural networks. ^[4] At Bitcoin's current price near $78,824, the traced coins carry a value of roughly $433.5 million. ^[5] CEL says former Intersango users may have claims against the traced pool, but each claimant needs evidence connecting an old account balance to the assets. ^[6] Current heuristic-based methods are prone to errors such as merging different users together. ^[7] Existing heuristic-based methods for identifying addresses belonging to the same user often produce flat cluster assignments with limited modularity. ^[8]