At present, the most efficient implementations of Arrowized Functional Reactive Programming (AFRP), such as Scalable FRP (SFRP), do not support the loop combinator. This prevents us from expressing many fundamental programs in such implementations, which prevent their use in domains where both performance and expressivity are required. We introduce Oxbow, which extends SFRP with support for the loop combinator by leveraging an improved variant of the rearrange technique. In benchmarks, Oxbow performs at least 2.2x better than Yampa, an AFRP implementation that supports the loop combinator.