why sell put assigned at market open instead of close

my sell puts order were assigned when market opened today, i thought it should be assigned at the time when the market close.

所有跟帖： 

• It is American option right? Buyer can exercise anytime -slow_quick- ♂ (0 bytes) () 03/21/2025 postreply 10:56:55

• yes, TESLA option provided by fidelity -CLM2020- ♂ (0 bytes) () 03/21/2025 postreply 10:57:42

• Fidelity does not "provide", you did -slow_quick- ♂ (0 bytes) () 03/21/2025 postreply 11:13:01

• you are right, i provide put order -CLM2020- ♂ (0 bytes) () 03/21/2025 postreply 11:15:23

• Put can be assigned at "any" time before expiration -三心三意- ♂ (0 bytes) () 03/21/2025 postreply 11:00:26

• ANY time of the option expiration day or before the OE day? -CLM2020- ♂ (0 bytes) () 03/21/2025 postreply 11:05:05

• Any time before expiration (it is decided by who bought it) -三心三意- ♂ (0 bytes) () 03/21/2025 postreply 11:09:33

• What are your strike prices? Do they expire today? -gladys- ♂ (0 bytes) () 03/21/2025 postreply 11:02:12

• the strike price is in the money and they expire today -CLM2020- ♂ (0 bytes) () 03/21/2025 postreply 11:07:11

• I sold SPY puts and they have been in the money for a long t -gladys- ♂ (145 bytes) () 03/21/2025 postreply 11:12:33

• 被assign了是好事啊。如果不想要，可以立即賣出call，又撈一筆premium -三心三意- ♂ (0 bytes) () 03/21/2025 postreply 11:17:16

• I will keep them for supporting elon -CLM2020- ♂ (0 bytes) () 03/21/2025 postreply 11:21:29

• 你的講法和胡楊好像 -gladys- ♂ (0 bytes) () 03/21/2025 postreply 11:23:24

• who is 胡楊? a celebrity? -CLM2020- ♂ (0 bytes) () 03/21/2025 postreply 11:25:19

• Link -gladys- ♂ (118 bytes) () 03/21/2025 postreply 11:28:53

• thank you for the link. certainly I am not the only one who -CLM2020- ♂ (40 bytes) () 03/21/2025 postreply 11:35:42

• Give you a case of why sometime you need exercise earlier. I -Girlsmom92- ♀ (787 bytes) () 03/21/2025 postreply 11:27:15

• ITM當天早上被assign太正常了，如果deep ITM，早幾個星期被assign都可能 -dancingpig- ♀ (0 bytes) () 03/21/2025 postreply 12:17:25