Depending on market conditions, I day trade SPX simple call and put options, on the last trading day. Since yesterday, I noticed huge spreads from time to time. So yesterday, I was thinking that is just because of a Fed day. I don't use option on Fed day. Also when IV of the SPX and the VIX spike, it is not unusual. Not the case today. Today, I see exactly the same huge spreads, specially with 2430 and 2420 puts that I follow this morning (June 16): At 11:22 ( I try to get out) 2430 = 4.50 / 6 for 2 sec, then 4.40 / 6.20 for a min 2420 = 0.85 / 1.10 for 5 sec, then 0.95 / 1.15 for a min At 11:26 2430 = 5.20 / 5.50 much better 2420 = 1 / 1.15 not great, out at 1.05 Does anyone know why? Fed day was obviously yesterday. My broker is IB.