USDJPY Pulls Back, When Is It a Reversal

Conviction is in the eye of the beholder. USDJPY has furthered its retreat with a notable break below 121.50 - former resistance that turned support. But does that signify a lasting reversal from the pair? To some, that is all that is needed. Those that are more conservative may require further tech levels being cleared, other yen crosses following suit or a more general effort to deleverage risk market-wide. At what level would you call it?