BS Bob: don’t worry!

Bob the Builder he ain’t.

Nasdaq CEO Bob Greifeld took to the airwaves yesterday in an attempt to assure investors and his Wall Street partners that everything was fine at the country’s No. 2 exchange.

Twenty-four hours earlier, Greifeld’s Nasdaq suffered an unprecedented three-hour meltdown, forcing investors around the country and the globe to sweat out yet another computer glitch.

Coming on the heels of it mucking up Facebook’s May 2012 IPO, perhaps Greifeld’s words yesterday were falling on deaf ears.

Wall Street is running away from Greifeld’s troubled electronic exchange, it would seem.

Where once the Nasdaq maintained an almost vise-like grip on new tech listings, including Facebook, during the first half of the year the rival New York Stock Exchange captured 64 percent of tech IPOs, NYSE said in a regulatory filing.

That doesn’t include the $156 billion-market-cap tech giant Oracle ditching Nasdaq for the NYSE in July — delivering a further blow to the tech exchange’s tech-listing dominance.

In his first public comment on the matter, Greifeld yesterday passed the buck for the embarrassing Nasdaq meltdown onto NYSE’s Arca platform.

“We stand by our performance over an extended period of time,” a stoic Greifeld told CNBC yesterday during one morning-show interview at Nasdaq’s office in Times Square.

The exchange head declined to accept direct responsibility for the trading outage that froze trading in nearly 3,000 publicly listed securities.

“We have to improve our defensive driving,” he said.

“We have to be aware that the other person will not always act in the proper way,” he noted.

Critics said that Greifeld’s tone and message mimicked a similar stance he took in passing responsibility on the Facebook screwup to other broker-dealer systems.

Ultimately, the Securities and Exchange Commission laid the blame for Facebook at Greifeld’s feet and fined the tech-heavy exchange $10 million.

The SEC is investigating Nasdaq’s role into this most recent market system failure, sources said.

Despite the numerous snafus and losing out on tech listings to the NYSE, Greifeld is in good standing with his board, according to people familiar with the situation.

“‘[Greifeld’s] still living off credit for being an astute cost cutter early in his tenure,” the source said, noting the exchange rising profits and stock price.

Nasdaq’s shares are up 37 percent over the past year.