# How to interpret the (expected) exposure and CVA of an option or a single share

I have a quick (hopefully simple) question regarding the interpretation of the expected exposure of a call option and a single share. I've done some computations on the formula for the expected exposure and this yielded that the expected exposure of both the option and the share, are equal to their initial value, i.e. $$EE(t)^{option}=V(t0)$$ and $$EE(t)^{stock}=S(t0)$$. I arrived at these results by using that both the discounted option value and the discounted stock value are martingales under the risk neutral measure. However, I'm reading mixed definitions on what just the term exposure actually is. Some say it is what you could lose on an investment, which would go well with my results, but others say it is what you could lose if things go bad, i.e. if you own a share worth 100 euros/dollars, then this is your exposure no matter what you purchased it for.

Could anyone help me in clarifying what the concept of exposure/expected exposure means for these two objects? The concept is slightly easier to grasp for swaps, but for products as 'basic' as these, it seems to be harder to understand. The same holds for how to think about the CVA of a single share, which I also have a hard time wrapping my head around.