twitter logo  Andreessen Horowitz invests $80 Million in TwitterIn an AllThingsD exclusive, we’ve just learned that Andreessen Horowitz, Silicon Valley venture firm has invested more than $80 million in Twitter via purchasing stock in secondary markets.

Andressen Horowitz did not invest in Twitter’s recent $200 million round, which valued the company at $3.75 billion.

With its last $200 million round, Twitter said in its blog,

“Growth is fun. In the past 12 months, Twitter users sent an astonishing 25 billion Tweets and we added more than 100 million new registered accounts. In that time, our team has grown from 130 people to more than 350 today.”

The VC firm told AllThingsD that since it is already deeply invested in other key companies in the social space, including Zynga, Foursquare, Groupon and Facebook, investing in Twitter made sense.

It is what some would call “a full house.”