At its March policy meeting the Bank of Japan switched its ETF buying solely into TOPIX (not the Nikkei225)

It also dropped its 6tln yen guide of yearly purchases

Since then the Bank has not bought ETFs since April 21, right though May and June so far. With the TOPIX down more than 2% today hopes are up for a BOJ intervention. If not on a day like today, then when? ... will be the question if they're absent. And that could send further chills through Japanese equities.