In light of preliminary data for JPY futures markets from CME Group, open interest and volume dropped by around 3.3K contracts and by around 9K contracts, respectively, at the beginning of the week.
The upside in USD/JPY seems to have met a tough hurdle near 109.40. Diminishing open interest and volume amidst the selling bias in the Japanese haven opens the door for a potential corrective downside in the pair in the short-term horizon.