The days of the Beardstown Ladies, this isn't. There's a lot of talk about bubbly stock market sentiment right now, but it's not evident in the declining interest in investment clubs. A group tracking the clubs says membership fell to 39K in 2012 from 400K in 1998. "It is quite frustrating to try to preach that long-term investing really pays off, when it just hasn't over the past decade." Check.