With Twitter surging on its first day of trading, there are lots of people who are suddenly #filthyrich.
Peter Fenton isn't a Twitter co-founder or executive, but he is the No. 2 individual shareholder with 6.7% of the company. That made him an instant billionaire on Thursday.
Fenton, a prominent partner at venture firm Benchmark Capital, backed Twitter in its very early days and now sits on the company's board of directors.
Benchmark Capital itself also owns a 6.6% share of Twitter.
NEXT: Jack Dorsey - $1.06 billion