Although this should go without saying, when swing trading, you will typically entry a sell limit order(s) at your price target(s) for long trades, using the GTC condition so the order remains open until the price target is hit. (best paired with a stop loss order using a OCO or OCA order).

A sell limit order will be filled at or better (never worse/below) than the limit price once that price level is reached or exceeded. When a stock gaps above your sell limit order, as UPS did today, limit orders are filled at the limit price, or better, never below it. In the case of a gap, no trades took place on or around the downtrend line today so any standing limit orders around that level would be been filled at the open today.