@arschles the naive strategy actually creates a thread on each evaluation https://github.com/scalaz/scalaz/blob/scalaz-seven/concurrent/src/main/scala/scalaz/concurrent/Strategy.scala#L79. Perhaps you want the Id strategy which is basically a no-op? https://github.com/scalaz/scalaz/blob/scalaz-seven/concurrent/src/main/scala/scalaz/concurrent/Strategy.scala#L72