After FireEye shares plunged 22 percent after reporting first quarter earnings on Tuesday, FireEye CEO David DeWalt was feeling the heat from the "Fast Money" traders on Wednesday.

"I can't control whisper numbers and what Wall Street is thinking high-growth companies can be," DeWalt said on CNBC. "One-hundred thirty-two percent growth, record numbers of new customers, expansion around the world is what we were doing. You know, we're very optimistic."

DeWalt's optimism didn't satisfy Brian Kelly of Brian Kelly Capital who had recently sold a losing position in FireEye.

Kelly pressed DeWalt on selling 485,656 shares in March at an average price of $79.54, days before announcing quarterly earnings.

"Now you're coming to us saying everything's fantastic, everything's great. Why were you selling? You've lost credibility with me. How do you get that back from Wall Street? That's why the stock is down 22 percent today. Nobody believes you anymore."

The CEO apologized.

"You know, my selling was consistent with all the executives, all the insiders," DeWalt said. "I still have 90-plus percent of all my holdings in FireEye. I'm highly motivated to grow shareholder value, and for a lot of the shareholders, we're going to work very hard to improve the value of this company over the long haul. I have a lot of track record of doing so. I apologize to you if you feel like you lost faith in me, but I'm going to work hard for you. I will be there."