*By Chloe Aiello* Tim Cook is an excellent steward of Apple, but he's no Steve Jobs ー and what Apple really needs right now, is innovation, said Andy Cunningham, who worked with Jobs to launch the Macintosh. "Tim Cook is an amazing steward of the assets he was left ... however, they have not been able to come up with the next big thing, which is really what they have to do. And Steve did it over and over and over and over again," Cunningham told Cheddar on Thursday. Apple ($AAPL) stock plunged 9 percent on Thursday, continuing its declines from Wednesday for its lowest stock pricing since July 2017. The losses followed a letter Tim Cook wrote to investors on Wednesday, adjusting Apple's first-quarter revenue guidance down significantly to $84 billion from a previous estimate of $89 billion to $93 billion. The new outlook is about 5 percent less than the $88.3 billion in revenue it reported the same quarter last year. [In the letter](https://www.apple.com/newsroom/2019/01/letter-from-tim-cook-to-apple-investors/), Cook mostly attributes the revision to "the magnitude of the economic deceleration" in emerging markets, especially China. "Most of our revenue shortfall to our guidance, and over 100 percent of our year-over-year worldwide revenue decline, occurred in Greater China across iPhone, Mac and iPad," Cook wrote in the note, adding that lower than anticipated iPhone revenue "accounts for all of our revenue shortfall to our guidance and for much more than our entire year-over-year revenue decline." The company has now lost about $420 billion from previous all-time highs, dropping it into place as the fourth largest publicly traded company, behind Microsoft ($MSFT), Amazon ($AMZN) and Alphabet ($GOOGL). Although Cook blamed China and its decelerating economy, Cunningham said it's all really about iPhone sales. "Apple missed on its iPhone and I think that's the real issue here," Cunningham said. "They blame the Chinese economy, primarily for the sluggish sales of the iPhone, but really I think underneath that issue is, I think, the fact that Apple really is in need of its next big thing." Despite the company's sizable cash horde, Apple prefers to invent in-house rather than acquire new products, Cunningham said, so what the company really needs is "a product visionary," like Jobs, to explore new ideas. Barring that, the company could be in trouble. " I think we are starting to see ー this may be an omen ー but we are starting to see the beginning of the last days of its heyday," Cunningham said. For full interview [click here](https://cheddar.com/videos/member-of-macintosh-launch-team-talks-apple-troubles).