# Intuitive explanation for - Shreve Vol 1 Ch 3 Lemma 3.2.6

I need help in getting a more intuitive understanding of this lemma 3.2.6 in Vol 1 of Shreve's Stochastic Calculus for Finance:

$\bg_white \widetilde{E}_n[Y] = \frac{1}{Z_n}E_n[Z_mY]$

Here, in the context of multi-period binomial pricing model, Y is a random variable that depends only on the first m toin cosses, where m is greater than or equal to n. Z is the Radon Nikodym Derivative process such that

$\bg_white Z = \frac{\widetilde{P}}{P} \\ \\ Z_n = E_n[Z]$

I understand the equation, and I can derive it mathematically by myself without any help too. Its just that I can't find an intuition behind it. Any kind of help would be great. Thanks !

• I would love to have an answer to this one as well! Oct 25 '20 at 21:14