Updated October 2026: Still broadly accurate, with corrections. Spark's own FAQ (docs.spark.money, checked today) says that if all operators go offline you can't make new transfers, but you can always exit to Bitcoin L1 with your pre-signed transaction, and it says Spark funds have no expiry. So my earlier point about balances expiring applies to Ark, not Spark. Ark's expiry is usually described as about 30 days in Spark's Ark comparison page and about four weeks in Ark design notes, so the exact figure isn't settled. On operators, Spark's FAQ names Lightspark, Flashnet and Breez as founding operators, while a Bankless post from last year counted two. The strongest case for your side is token issuance: Spark's Issuer SDK lets a token issuer freeze addresses for its own stablecoins. That is a real freeze power, but it covers tokens issued on Spark, not plain bitcoin. On Ark, the service provider can refuse new rounds and, after expiry, sweep unrenewed balances; the Ark design paper (docs.arklabs.xyz) says users must exit before expiry to keep their coins. A recent Bitcoin Train piece also reports that many popular Spark wallets still depend on operators to supply data a unilateral exit needs, so the exit right is only as usable as the wallet's software. My read: the code is open and the exit right is real, but the practical squeeze is on liveness, expiry and, for tokens, the issuer.
🕒 Updated October 2026
