Shaw Wu: How Apple gets its Wall Street mojo back

February 5, 2013, 12:47 PM UTC

FORTUNE — “The big question we get from investors is whether the greatest turnaround and growth story of the past decade is over?”

So begins a note to clients issued Tuesday morning by Sterne Agee’s Shaw Wu. His short answer is “no.”  His slightly longer answer is that Apple (AAPL) needs to think different to regain its “mojo.”

How exactly does it do that? Wu offers a four-step program:

1. Make a bigger iPhone. “In many markets, the 4.8- inch (Samsung Galaxy S III) to 5.55-inch (Galaxy Note II) form factors are the new high-end of the market where the iPhone 5 is viewed as mid-range but with a high-end price.”
2. Reclaim the high end. “We believe AAPL is leaving money on the table by not participating in larger touchscreen form factors. But more importantly, we believe AAPL needs to reclaim high-end leadership as that is what its brand is about.”
3. Address the mid-range better. “The iPhone 4 and 4S are highly desired by many but not as widely available as they could be… We believe this isn’t because of components but because iPhone 4 and 4S manufacturing capacity had been scaled back in favor of iPhone 5.”
4. Let the margins fall. “Investors have shown a willingness to accept lower margins for sustainable top-line growth. We have seen this with Amazon (AMZN) and Google (GOOG).”

Wu rates Apple as a “buy” with a $715 price target. Apple closed Monday at $442.32, down $11.30 (2.49%) for the day. The stock could use some mojo.