LoopCoder-V2 is a 7B instruction-tuned code model based on Parallel Loop Transformer (PLT), trained on 18T tokens of mixed text and code data. The two-loop variant achieves the best gain-cost balance, improving SWE-bench Verified from 43.0 to 64.4, while three or more loops result in regression due to increasing positional mismatch and unstable updates.