I live southwest (roxborough). Don't know if there's much of a community though, invesco has some presence downtown and there are some independent folks in boulder.
I haven't been to Denver in years. Even though my dad grew up in the area. Sometimes I do think I'd like to retire in that general region though.
Grew up in Lisle. College in Elmhurst. Lived in Aurora/Naperville and Mt Prospect. Moved here (SW Littleton/Roxborough) last August. I FUCKING LOVE LIVING HERE and I'm not an outdoors guys at all. The weather and mountains (view) is what does it for me. Everything you've heard about the lower (but not too low) humidity is true. You know how you sweat walking to the mailbox? Nope. Right out of the shower and you need another one? Nope. Grey all winter especially March? Nope. Now, the sun itself is VERY intense compared to Chicago so that's a bit of a drag if you weren't a 'sunscreen all the time guy.' I literally have to goop up to mow the lawn, and the lawns are small out here. And let's face it, the total population of the area is about 2.5 mil for the 10 county region. Chicago and the surrounding area is what, 9.5+ mil? So don't expect 10 Charlie Trotter caliber restaurants. There's just not the higher end entertainment stuff like Chicago. But if you don't care *that* much about it, it's totally worth it. I wish I'd moved here 20 years ago.
I'm not in Denver, but I have heard some in Denver mention a trading group. Here's the link. http://denvertradinggroup.com/ Just FYI.