Twitter investor GSV Capital jumps on IPO filing

• GSV owns Twitter stock that was worth %2438 mln on June 30
• GSV shares jump almost 17%25 in after-hours trading
• GSV%27s pre-IPO investment in Facebook produced mixed results

Twitter's private IPO plans have already had an effect on the public stock market.

Shares of GSV Capital, a publicly traded firm that holds private shares in technology start-ups including Twitter, surged 16.8% to $14.18 in after-hours trading on Thursday.

GSV, run by former tech investment banker Mike Moe, invested in Twitter common and preferred shares in April, June and July 2012, spending about $33 million. As of June 30 this year, the firm's stakes were worth $37.6 million, according to SEC filings.

That valuation suggests that Twitter stock was changing hands in the so-called private secondary market for around $19.80 per share at the end of June.

If Twitter completes its IPO and the public stock climbs, GSV could generate big gains. However, it is not guaranteed to work out that way. GSV bought private shares in Facebook before that company's IPO in 2012. When that offering flopped, GSV shares slumped below $8 in late 2012.