English to Russian Bus/Financial Finance (general) Option pricing

Перевожу слайды к лекции. Речь идет о биномиальной модели оценки опционов и replicating portfolio. Эти short и long появляются постоянно. Не догоняю, как сказать. Здесь нужен человек, реально профи в опционах, потому что с контекстом тяжело - придется просто весь текст подряд приводить. Я и раньше переводила про опционы и эту модель, но вот эти термины не встречала.

Попытка контекста:

Let D be the number of shares of stock purchased, and let B be the initial investment in bonds.
To create a call option using the stock and the bond, the value of the portfolio consisting of the stock and bond must match the value of the option in every possible state.
In the up state, the value of the portfolio must be $10.
In the down state, the value of the portfolio must be $0.
Using simultaneous equations, D and B can be solved for.
D = 0.5
B = –18.8679
A portfolio that is long 0.5 share of stock and short approximately $18.87 worth of bonds will have a value in one period that exactly matches the value of the call
60 × 0.5 – 1.06 × 18.87 = 10
40 × 0.5 – 1.06 × 18.87 = 0
(60 и 40 - подорожавшие и подешевевшие акции через один период, 6% - безрисковая ставка, здесь по облигациям)

Попытка контекста 2:
Suppose a stock is currently trading for $60, and in one period will either go up by 20% or fall by 10%.
If the one-period risk-free rate is 3%, what is the price of a European put option that expires in one period and has an exercise price of $60?

Solution:
We begin by constructing a binomial tree:
Thus, we can solve for the value of the put by using Eq. ХХХ and Eq. ХХХ = 0 (the value of the put when the stock goes up) and Cd= 6 (the value of the put when the stock goes down).
Therefore [здесь тоже формула]
This portfolio is short 0.3333 shares of the stock, and has $23.30 invested in the risk-free bond.
Let's check that it replicates the put if the stock goes up or down:
72(-0.3333) + 1.03(23.30) = 0 and 54(-0.3333) + 1.03(23.30) = 6
Thus, the value of the put is the initial cost of this portfolio.


Собственно формулы привести не могу - они embedded в ppt. Редко что программа распознала.

Поможите, кто умный и догадливый!