SAN FRANCISCO - Just about everyone in Silicon Valley has dreamed of striking it rich with a well-timed investment. Here is a list of the number and value, based on the closing price of $44.90, of the shares owned by some of the people and investment firms that have benefited the most from Twitter's initial public offering on Thursday. At the market close, Twitter's valuation was $24.47 billion.

Executive officers and directors:

Evan Williams - 56,909,847 shares, or 12 percent, worth $2.56 billion. Williams was Twitter's chief executive until 2010, when current CEO Dick Costolo took the helm. He is working on a publishing platform, Medium, which is dedicated to long-form content.

Benchmark - 31,568,740 shares, or 6.7 percent, worth $1.42 billion. Venture firm Benchmark started investing in Twitter in 2009 when it was valued in the $200 million-$250 million range. This stake includes shares owned by partner Peter Fenton, who led the firm's investment in consumer-Internet play Yelp, holds a board seat at Twitter.

Jack Dorsey - 23,453,017 shares, or 4.9 percent, worth $1.05 billion. Dorsey co-founded Twitter and still serves as its chairman. In 2009, he founded payments service Square and serves as its CEO.

Dick Costolo - 7,675,239 shares, or 1.6 percent, worth $344.6 million. A onetime improvisational comedian, Costolo took the helm of Twitter in 2010. He joined Twitter as chief operating officer the year before, after he and co-founders sold their Web feed management provider FeedBurner to Google Inc

Adam Bain - 1,785,818 shares, or less than 1 percent, worth $80.2 million. Bain is the president of global revenue at Twitter. He was formerly the president of audience network at News Corp's Fox Interactive Media.

David Rosenblatt - 291,666 shares, or less than 1 percent, worth $13.1 million. Rosenblatt is CEO of luxury online retailer 1stdibs.com and is a member of Twitter's board of directors.

The following groups own at least 5 percent:

Rizvi Traverse Management - 85,171,093 shares, or 17.9 percent, worth $3.82 billion. A closely held private-equity fund based in Michigan, Rizvi has made a name for itself by buying stakes in entertainment companies such as Playboy and movie producer Summit Entertainment. Last year, it led a $200 million funding round in Jack Dorsey's payments company, Square. This stake includes shares over which JP Morgan has dispositive power.

Spark Capital - 32,414,224 shares, or 6.8 percent, worth $1.46 billion. Venture firm Spark started investing in Twitter in 2008. For a time, Spark partner Bijan Sabet served on Twitter's board.

Union Square Ventures - 27,838,992 shares, or 5.9 percent, worth $1.25 billion. Venture firm Union Square started investing in Twitter in 2008. For a time, USV partner Fred Wilson served on Twitter's board.

DST Global - 23,744,745 shares, or 5 percent, worth $1.07 billion. The investment firm founded by Russian billionaire Yuri Milner led a $400 million investment in Twitter in 2011. At the time, Twitter was valued at around $8 billion.