(AP) -- The CEO of the Nasdaq stock exchange says it is "humbly embarrassed" by its bungling of Facebook's hugely anticipated debut as a public company on Friday.
Robert Greifeld tells news media there's no indication the delay contributed to the underwhelming performance of Facebook's stock, which ended at $38.23 - 23 cents above where it began.
Facebook's stock was expected to start trading at 11 a.m. but didn't open until 11:32 a.m., and some investors didn't learn for hours whether their orders went through.
Greifeld called the social network's first day of trading "successful." He said late order cancellations caused a glitch, according to reports published Sunday. He said Nasdaq's board met Saturday and plans to change its IPO auction process.
The Securities and Exchange Commission has said it is investigating.
Explore further: Struggling BlackBerry announces new round of layoffs