The hyperactive Apple (NASDAQ:AAPL) rumor mill is unlike any other. Given Apple's sprawling global supply chain, it's not easy for the company to keep secrets. For this reason, the rumor mill has occasionally offered decent tidbits. That said, it's still mostly littered with material that is useless for long-term Apple investors. Those shareholders who pay attention to these rumors should take them with a grain of salt.

Here are two examples of recent Apple rumors investors would be better off ignoring completely.

Apple Store China

A 3-D printer from Apple?
It's beginning to look like Global Equities Research's key reason for hiring analyst Trip Chowdhry to cover the tech giant was to add humor to Apple media coverage. The analyst has made several outlandish claims, and they seem to just keep getting crazier.

Chowdhry's most recent prediction? Apple is going to enter the 3-D printing market. Such an extreme statement should be backed by extreme evidence, but that's not the case at all. MacRumors' Kelly Hodgkins asserted that Chowdry's claim is "nonsensical":

Chowdhry provides little to no details on Apple's 3D printing plans, citing only the company's experience in hardware and its intellectual property covering the technology as substantiation for his prediction.

Earlier this year, Chowdhry told CNBC that Apple would "disappear" if it didn't introduce an iWatch within 60 days. His 60-day countdown ends Monday. It's hard to say whether the Apple 3-D printer rumor or the iWatch death timer is more humorous.

NFC technology in the iPhone 6
It's evident that Apple is working on some sort of payments solution. During the company's fiscal first-quarter earnings call in January, CEO Tim Cook acknowledged that it's an area the company has "been intrigued with" and that it "was one of the thoughts behind Touch ID." Meanwhile, Re/code reported last month that Jennifer Bailey, Apple's e-commerce chief, was assembling a team to oversee a mobile payments initiative.

Apple Touch Id

Touch ID on iPhone 5s. Image source: Apple.

But recent rumors that Apple will use near field communication, or NFC, technology as the platform for its alleged payments service may not be as substantiated as they appear. Sure, reports making a case for Apple to adopt the technology are convincing. Morgan Stanley, BrightWire, and reliable longtime Apple analyst Ming-Chi Kuo are all predicting the iPhone 6 will debut a payment service featuring NFC technology. Morgan Stanley was the most recent source of NFC-Apple chatter, stating that NXP Semiconductors would likely provide the wireless hardware for the payment system.

Rumors that Apple will introduce an NFC-backed payment service arise annually, and nothing has ever come of the rumors. While it's possible that these rumors are true, it wouldn't do Apple investors any good to bet on such a speculative rumor.

The key lesson for investors? Study the rumors before you adopt them into your outlook for Apple's business. And even if the rumors look legitimate, the majority of rumor mill chatter is useless to long-term Apple investors. Stay focused on the bigger picture.

Here's an Apple rumor you can bank on, but not by buying Apple
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Daniel Sparks owns shares of Apple. The Motley Fool recommends Apple and NXP Semiconductors. The Motley Fool owns shares of Apple. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.