Techniques for efficient continuation stack storage are disclosed. In some embodiments, when a continuation yields, the continuation stack, or portion thereof, is copied from a thread stack to a data object, referred to herein as a chunk, allocated from memory. The copied stack portion may maintain the same representation in the chunk as on the thread stack to minimize processing overhead of the operation. When the continuation resumes, the continuation stack, or some portion thereof, is copied from the chunk to the thread stack. During execution, the continuation stack that was copied may be modified on the thread stack. When the continuation yields again, the runtime environment may determine, based at least in part on whether the first object in memory is subject to a garbage collection barrier, whether to copy the modified portion of the continuation stack to the existing chunk or to allocate a new chunk.