Day 4 was less productive than usual. This can probably be attributed to the fact that only Campbell and I were in the Nucleus this morning. That third and fourth person seems to make a difference.
I spent the morning engaging people in discussion on Quora and Reddit and seemed to get some interest. There was one redditor who was actively engaged (he has written easily over 500 words in response to a few of my forum questions).
Later in the day, I got to work on my customer personas, which are archetypal characters used to demarcate my users' behaviour, motivations and expectations. I created a 2x2 matrix outlining my potential investor types. On the x axis is the level of profit-seeking interest - that is, the degree to which the customer is interested in profiting from their investment. My research has revealed that there are members of my target demographic whose primary concern is not to make money (this is easily to say when they are investing only a dollar). Rather, they are more concerned ideological foundation of their investment and supporting a company whose practices they believe in. In this matrix, Sarah embodies this outlook. Once I begin to develop the game layer of my site, I imagine there will be another dimension that assesses the level of interest in scoring well within the investing game - a "game interest" dimension, if you will. 
The y-axis of the matrix above ranks the users emotional attachment to their investment. Both David and Josh are not concerned with the type of stocks they invest in so long as they are profitable. What separates David and Josh is their activity on the site. David is an actively involved user; he is calculating and assiduous. He enjoys intensively researching the companies, and continually checks the stock price. Josh, on the other hand, sees the site simply as a low-cost way of making money. He only enters investment groups he knows have "experts" in them, and doesn't want to commit the time or energy required to make research his investments. He defaults his vote to David and Lynn type users. Lynn is a combination of both the David and Sarah personas. She is an active, and research heavy investor; however, she invests primarily in companies she supports for ideological reasons. He seeks to develop a close relationship with the company management, and is more likely to be a long-term investor.
To make these customer types real, I not only named them, but I gave them faces. The purpose of this is simple: personifying my customer segment subtypes not only helps me better remember them, but it continually reminds me that I am developing this product for real people. This seems to be something that is easily to lose track of. After all, as Eric Ries says, "Metrics are people too".
While I only have four personas at the moment, I will likely have more in the future. I also need to work more on identifying the personas' expectations and behaviours, but this will come with time.
