Why did Apple pop in after-hours trading Wednesday…

July 19, 2012, 8:27 PM UTC

AAPL jumped right after the markets closed

FORTUNE — It’s not terribly surprising that Apple’s (AAPL) shares rose $8.23 (1.36%) in Thursday trading.

An hour before the markets opened, Verizon (VZ) reported that it activated 2.7 million iPhones last quarter, down from the previous quarter but somewhat better than analysts expected.

The results helped alleviate Morgan Stanley’s concerns about Apple’s third-quarter iPhone sales, Katy Huberty told her clients. They made Piper Jaffray’s Gene Munster “incrementally more comfortable” with his own iPhone estimates.

Fair enough.

What’s harder to explain is why Apple’s shares rose sharply right after the markets closed on Wednesday, more than 16 hours before Verizon’s results were released.

Just one of the mysteries of the stock market, I guess.