Can we catch systems before they secretly fall apart?

Recursive systems (markets, recommenders, LLM training loops) can degrade invisibly while amplifying feedback until sudden failure. Loopzero is a benchmark framework that tests whether detectors can spot the telltale pattern: rising gain, persistent recursion, declining diversity—under a fixed false-alarm budget so all methods face equal constraints. On stock-market crashes and movie-recommendation systems, neither standard methods nor the proposed detector hit acceptable performance, but the directional pattern itself held on real data.