I'm reading Nassim Taleb's book "Dynamic Hedging", on page 22 he says:
Consequently, a straddle will be qual to two calls delta neutral or two puts delta neutral (of the same strike). Assume that the forward delta of a put is 30%,
$$Straddle = 2P + .6F = 2(C-F) + .6F = 2C - 2F + .6F = 2C - 1.4F$$
I really couldn't understand this, according to wiki straddle page "A straddle involves buying a call and put with same strike price and expiration date", so $$Straddle = P + C$$
In Taleb's example, he's assuming $C = 0.3F$ and $P = -0.7$, so
$$Straddle = P + C = -0.7F + 0.3 F = 0.4F $$
This doesn't tally with his equation $Straddle = 2P + .6F = 2(C-F) + .6F = 2C - 2F + .6F = 2C - 1.4F$. What's the catch?