Rootstock, the Bitcoin sidechain formerly known as RSK, is grappling with a liquidity squeeze after users attempted to withdraw funds simultaneously, temporarily exhausting the UTXO inventory of its two-way bridge. The result has been withdrawal delays stretching well beyond normal processing times, prompting the project's developers to explain the mechanics behind the slowdown.
Developer Sergio Demián Lerner addressed the situation on X on September 8, 2026, attributing the surge in withdrawal requests to user concern following a recent incident on Liquid Network, another Bitcoin sidechain, where an attacker managed to steal 4,000 bitcoin. That theft was previously reported by CriptoNoticias. Lerner described the reaction on Rootstock as behaving like a bank run, with users rushing to pull funds at the same time out of caution rather than any confirmed problem on Rootstock itself.
How the bridge got squeezed
Developer Adrian Eidelman offered a more technical account of what happened inside the PowPeg mechanism, the system that manages transfers between Rootstock and the Bitcoin main network. He explained that the bridge's UTXO inventory has been left with a single large UTXO. Each peg-out, meaning each withdrawal from Rootstock back to Bitcoin, returns almost all of the bridge's remaining balance as change from that transaction.
That change cannot be reused immediately. Bitcoin network rules require 100 confirmations before the returned funds can be spent again, which is what has created the bottleneck as demand for withdrawals spiked all at once.
Delays capped, not compounding
Lerner estimated that withdrawals are currently taking between 36 and 46 hours, describing this as roughly 10 additional hours on top of the mechanism's regular processing time. He clarified that a single outgoing transaction can group multiple user withdrawal requests together, meaning the delay does not accumulate with every additional withdrawal request. The wait time, he said, caps at 46 hours regardless of how many users are trying to exit at once.
As an immediate mitigation measure, the Rootstock team said it will seek actors willing to perform multiple small-sized peg-ins, the reverse process of moving bitcoin into the sidechain, in order to create new UTXOs for the bridge to work with. Restoring a more diversified set of UTXOs is intended to bring processing times back to normal.
Both Lerner and Eidelman stressed that, while the delays have affected user experience, the behavior reflects how the PowPeg mechanism was designed to function under a sudden surge in demand rather than a malfunction or security failure.
