JPY vs USD, key to the other index developments. As long as it holds its trendline, JPY will remain week vs the other global currencies, Japan exports will hold, carry trade arbitrages won't unwind, US bonds will not sell off (rising yields), volatility will remain contained.
But if it breaks and doesn't hold the 139JPY/$, we could witness how algos start dumping US and Euro shares and bonds. Rising JPY should also affect the Nikkei 225, retaking the path to 30k