Spark (Lightspark) Spark is an open-source L2 by Lightspark (David Marcus, ex-PayPal / ex-Facebook) launched April 2025. Builds on statechain concepts with FROST threshold signing and a leaf-based structure for partial transfers. Architecture Core components: - Spark Operators (SOs) : collective threshold signers, FROST k-of-n. - Leaves : terminal off-chain UTXOs owned by users; each has a relative-timelock exit transaction. - Trees : hierarchical structure supporting partial-balance transfers. Leaves Each Spark leaf is: - An off-chain UTXO with FROST-aggregated multisig. - A relative-timeloc…