Haiku

Caffiene headache hurts
Coffee makes it go away
Addiction still there

No attempt to break
The pull of coffee on me
Too hot to drink it

Fill cup up early
Forget about it til lunch
Problem solved, it's cold




the maths (of a financial ecomonics sort):

Put-call parity
Call plus present strike equals
Put plus forward price

Call is S less K
And for Put it's K less S
Max(above and naught)

I hate arbitrage
buy/sell/short the put/call/stock
which is when and why?