SAN FRANCISCO — Twitter’s financial filing for its Wall Street debut was chock-full of juicy tidbits, from the name of its richest founder to a list of its escalating losses. But one revelation was particularly startling: Just a single woman among its top officials.

The board? All white men. The investors? All men. The executive officers? All men but for the general counsel, Vijaya Gadde, who has had the job for five weeks.

“This is the elite arrogance of the Silicon Valley mafia, the Twitter mafia,” said Vivek Wadhwa, a fellow at Stanford’s Rock Center for Corporate Governance who is writing a book on women in tech. “It’s the same male chauvinistic thinking. The fact that they went to the I.P.O. without a single woman on the board, how dare they?”

Even as women make significant headway in fields from law to business, and technology zooms along as one of the fastest-growing sectors of the economy, its doors remain virtually closed to women. Just 5.7 percent of employed women in the United States work in the computer industry, and only about 2 percent of women have a degree in a high-tech field, according to Catalyst, a prominent research firm studying women and business.