While Apple was dipping in after-hours trading after its earnings were announced, one Twitter investor has decided to get off of the tweetbus.

Howard Lindzon announced the move via Twitter, naturally:

Lindzon is an angel investor, as well as the CEO and Co-founder of Stocktwits, which is a real-time site that lets you get information about the companies you’re interested in investing in. He passed on investing in Twitter early on, but made his way into the club with the sale of Tweetdeck.

Here’s Lindzon’s bio from his site:

I am an active angel with many success investments including: Rent.com, (purchased by Ebay in 2005 for $415 million), Golfnow.com (purchased by Comcast in June 2008), and Lifelock (lead investors include Bessemer Venture Partners and Kleiner Perkins Caufield & Byers). Other investments include: Limos.com, Blogtalkradio.com, Buddy Media, Ticketfly, Assistly, Bit.ly, Etoro.com, Tubemogul and Tweetdeck (purchased by Twitter).

If I don’t invest in your company, take heart in the fact that I passed on Twitter, Zynga and Foursquare early on as well.

Since Lindzon is an accomplished third-party developer, does this mean that there are dark days ahead for services built on top of tweets? Note that Lindzon mentioned that he’s long on Apple. I suppose that means that the same feeling doesn’t ring true for Twitter, which is not yet a publicly traded company.

We’ve reached out to Lindzon for comment and will let you know if we learn anything more.

UPDATE: Howard Lindzon was kind enough to jump on the phone with me to discuss his decision, and it sounds like he’s taking this as an opportunity to invest in more things that he believes in:

I’ve been lucky to have been involved, as well as having the opportunity to get out.

He believes that Twitter could be around for “100 years”, and let’s hope he’s right.