CLOSE: UPL Naked Put +21.9%

On 5/15/08 I SOLD JUN 80 PUT @ $2.80 credit
Risk= $10.26 margin held
My exit order was set for $0.56 (80% of my credit)
Set my stop loss for twice the credit at $5.60.

Today my exit order was triggered at:
BOT +16 UPL 100 JUN 08 80 PUT @ $0.55 debit

2.80-0.55/10.26 margin= 21.9% in 18 days