the price of the underlying asset does not move substantially in either direction.
A short straddle looks like a mountain or an iceberg, with most of its
mass underwater (i.e., below zero). Notice how little of the straddle is above
zero, compared to the total profit-and-loss profile. The portion of the short
straddle that is above zero depends on the size of the premium relative to
the total exposure.
Combining a Short Straddle and a Long
Futures Contract
It is important to remember that the short straddle positions taken by Leeson
did not occur in isolation. As Exhibit 7.5 shows, Leeson combined his
short straddles with long futures positions.
For every straddle he sold, Barings got cash, and Leeson used the cash to
pay the required initial margin deposits on new trades and also to meet the
mounting margin calls on his existing stock index futures positions. Exhibit
7.5 shows that, to profit from the long futures position, the stock price had
to rise above the futures price,15 but if it rose too much, every yen of gain
made on the futures position would be offset by losses on the short straddle
(or more specifically on the short call portion of the straddle). On the down
side, the situation was much more risky. A decline in the stock price caused
simultaneous losses on the futures position and the straddle position (or
more specifically, the short put portion of the straddle). The only thing