Apple's value has grown by $54 billion since Monday

Apple stock is in the middle of a torrid three day rally.

Apple stock was up more than 4% in midday trading on Wednesday to $112.64 per share. The stock opened at $102.68 on Monday, so it's up nearly 9.5% for the week, adding almost $54 billion to Apple's market cap.

For reference, consider that Twitter's entire market cap is $12.7 billion. Netflix has a $42 billion market cap.

Of course, Apple is the most valuable company in the world, with its total market cap now standing at a whopping $605.68 billion.

The sudden surge in Apple share appears to have been sparked by signs that the new iPhone 7, which hits store shelves on Friday, may outperform lackluster sales expectations.

Carriers like T-Mobile have said their iPhone 7 preorders are beating expectations, and gadget reviewers who have gotten their hands on the iPhone 7 have been generally impressed (though not necessarily blown away).

Analysts are picking up on the positive signs as well.

"We believe healthy August sell-through and lean iPhone 6s inventories in conjunction with more assertive carrier promotions set up for a better-than-expected iPhone 7 launch," Pacific Crest Securities analysts wrote in a note distributed to clients on Wednesday.

The current price is a 5-month high for Apple, and shares traded hands on Wednesday at nearly double the average daily volume.

Here's the daily chart:

Here's what Apple has done over the past five days: