1The course or development of events; how things progress; the outcome.
会議の成り行きに任せることにした。
We decided to leave it to the course of the meeting.
成り行きで予定を変えた。
We changed our plans as things unfolded.
この問題の成り行きを見守ろう。
Let's watch how this issue develops.
2Short for 成り行き注文 (market order) — an order to buy or sell at the current market price without specifying a limit. In financial contexts, often written as 成行.
株を成行で100株買った。
I bought 100 shares at market price.
成行注文は素早く約定するが、価格変動リスクがある。
Market orders execute quickly but carry price fluctuation risk.