Large institutional investors due to disclose their holdings in Apple, Inc. August 15

A surprise tweet by Carl Icahn on Tuesday voluntarily disclosed a "large position" in Apple, but this week all institutional investment managers face a deadline for reporting their holdings of securities worth at least $100 million.

Icahn was reported by Bloomberg to now own a stake in Apple worth more than $1 billion, and cited an unnamed "person with knowledge of the purchase" in saying that Icahn had "accumulated the position over the past month."

The U.S. Securities and Exchange Commission requires large investors to report their significant holdings, but only about a month and a half after the quarter ends, as AppleInsider reported in mid-February.

The deadline for other major institutional investment managers and investment advisers to disclose their common stock holdings and put or call options (as of the end of the June quarter), is August 15, submitted as SEC Form 13F.

Disclosures, but only every three months

In mid-February, a series of reports (such as one by Aaron Pressman for Reuters) detailed institutional investors that had "dumped" Apple shares, even though many of the largest sellers continued to own vast holdings (below).

Source: Fortune

Pressman blamed Apple's drop on "investors worried about increasing competition and declining profit margins," and, conversely, explained that "the shares also may have dropped because their price rose too much, too fast."

He also cited an analysts as saying "three months from now, we'll be seeing a lot of the people who sold starting to pick it up again."

Three months later, there was again a steady trickle of reports of institutional investors "dumping" shares in Apple, information culled from 13F regulatory filings. This "news" was presented without context or explanation of any kind by sites such as BusinessInsider, or alternatively, occasionally framed as worthy of dire concern.

Vikas Shukla of ValueWalk wrote that Apple "continues to lose charm among shareholders," based on reports of its shares being "dumped" by several large mutual funds including "Fidenlity Contrafund" [sic].

"These sell-offs by key investors bodes trouble for the iPhone maker," wrote Meghan Foley for Wall St. CheatSheet.

Apple shares have gone up more than 10 percent since those mid-May reports first appeared, reciting as "news" information that at the time of their publication was already six weeks old.