The price plunged leaving behind a massive inefficiency or FVG (fair value gap).
It is likely to retrace back into the FVG or all the way into an OB (order block) above.
Wait for the price to tap into the FVG or into the OB, then switch to a 15min time frame. In the 15min look for a trend change and an OB that caused the trend change. Then place your limit order just below the OB, your stop loss should be just above the 15min OB, and your TP on the extreme lows on the 4h timeframe