Weak analogy indeed. Stock investment is not done by rolling a die, or listening to what some random person says is gonna happen. It's an analysis of historical stock value, and a knowledge of what the companies are you're investing in and what condition they're in.
If he said playing the lottery with the numbers a psychic tells you to use, that would have been a closer analogy. But the stock market isn't the lottery, it's not random. Unpredictable, yes. Random, no.
The weather forecast is often wrong too. But again, it's not random.
For an academic to say such a lame thing is kind of embarrassing.
EDIT: Actually, there's another way in which is this is wrong. Stock investment is associated with risk. It's like gambling, you know full well that you're not making a safe choice. Which is not much religion is it, religion isn't associated with risk, people generally feel safe about their choices.