Friday, 8/24/2018 (Expiration Friday)
Trade 1 (8:29:32 am, PT) ← SPX trading around 2872
sell -4 August 24, 2018 2865 puts at $1.05 (delta 21.75)
buy +4 August 24, 2018 2835 puts at $0.05 (cheap wings)
Trade 2 (9:04:16 am, PT)
buy back short puts (2865) at $0.50 (to take profits)
Trade 3 (9:33:09 am, PT) ← SPX trading around 2874.50)
sell again -4 August 24, 2018 2865 puts at $0.55 (delta 12.58)
Trade 4 (12:23:18 pm, PT)
buy back short puts (2865) at $0.05 (to remove the risk)
PROFIT: $400 (in 3.5 hours)
Note: SPX closed at 2874.69 at 1:00 pm, PT