Market nuked IEX on account of fears in the market that IEX will most likely lose its monopoly status in the market once the market coupling mechanism is implemented. This could be a "shakeout".
Weekly close below 144 won't be particularly positive , but if it manages to hold 143-144 , then it can be an opportunity to buy (purely from TA perspective) , but if already holding from lower range, one should avoid adding more risk here.
SL would be below 125 weekly close.