Editor's Note: This article was originally published on Real Money at 1:20 p.m. on July 5.

Hedge fund Pershing Square's main investment fund -- which has been teetering on the verge of negative territory since Valeant Pharmaceuticals (VRX) began thrashing returns last fall -- is now officially in the red.

Bill Ackman, the billionaire activist investor and Pershing's CEO, rolled out his hedge fund's results just as the Fourth of July weekend commenced Friday, posting a 3% loss for the month (before accounting for fees), dragging the fund's gross 2016 loss on the year to just over 20%.

As Real Money reported, Ackman's Pershing Square -- which was founded in 2012 and converted into a closed-end fund in October 2014 -- was on the cusp of negative returns in May, posting a 0.2% return net of fees since its 2012 inception.

Ackman listed 11 long positions in the fund's June results, along with Pershing Square's short stake against nutrition products distributor Herbalife (HLF - Get Report) . But no position was quite as damaging to Pershing's portfolio as Valeant Pharmaceuticals, which lost more than a quarter of its market cap in June alone.

Shares of the troubled Canadian drugmaker are down more than 92% since their late-July highs last year, which followed a string of acquisitions that Ackman and his Pershing team applauded, especially the roughly $11 billion purchase of Salix in April and the $1 billion acquisition of Sprout Pharmaceuticals in August.

"Despite a substantial increase from our purchase price earlier this year, we believe that Valeant shares remain undervalued," Ackman said in a semiannual Pershing performance update last summer. Pershing upped its stake in Valeant to 5.7% last March for an average price of $196 a share.

However, Ackman's acquisition spree came at a cost to shareholders and to a handful of debt holders since Pershing issued an $1 billion bond issuance last August. (Pershing Square's senior unsecured notes, maturing in 2022, were most recently quoted at $96.55 on the dollar, down from $102.90 highs last summer.)

The $31 billion debt stack that Valeant has accumulated has caused many investors to flee over the past 12 months, especially as controversy surrounding Valeant's drug pricing culminated in a Senate Special Committee hearing in April and the departure of Valeant's former CEO Michael Pearson.

Valeant's former partnership with mail-order pharmacy Philidor also led to a Securities and Exchange Commission investigation, the delay of Valeant's annual and quarterly filings, and an admission to about $58 million worth of improperly booked sales.

Ackman and Pershing Vice Chairman Stephen Fraidin recently obtained board seats on Valeant as part of the drugmaker's management reshuffle, which has included the induction of Perrigo (PRGO - Get Report) veteran Joseph Papa as CEO.

The new management team has repeatedly attempted to reinforce its commitment to refurbishing its brand as a patient-first drugmaker, highlighting that asset sales will be necessary to cope with the $31 billion debt burden and looming maturities.

Pershing's other major long positions included Mondelez (MDLZ - Get Report) , the food and beverage giant that Ackman revealed a 7.5% stake in last August, which was acquired at an average price of $40 a share.

Shares of Mondelez, which traded at about $45.35 in midday trading Tuesday, were buoyed last week on rumors that it had approached Hershey (HSY - Get Report) with a $107-per-share takeover bid, representing a roughly $23 billion offer.

Hershey rejected the offer shortly after it surfaced, and Real Money' contributor Chris Laudani wrote Tuesday that such a tie-up stilll would be a "disaster," noting Mondelez is in much need of building up its North America sales, which account for just 27% of its annual revenue vs. about 90% of Hershey sales.

"The snack maker is desperately trying to fill a hole in its strategy, a strategy that I believe needs serious reworking," Laudani added.

The other major food maker in Pershing's portfolio is Nomad Foods (NOMD - Get Report) , the Virgin Islands-based frozen foods distributor in which Ackman disclosed a nearly 22% stake last July, representing a roughly $350 million investment.

But Nomad shares have fallen more than 30% so far in 2016 amid negotiations with unions following the March decision to shutter its flagship factory in Sweden, which will require about 500 job cuts and direct costs to Nomad of roughly €50 million, or about $55 million, the company said on its first-quarter earnings call with analysts.

Pershing's other major long stakes include Canadian Pacific Railway (CP - Get Report) and Platform Specialty Products (PAH) , which fell roughly 9% and 11%, respectively, in June, as other positions such as Air Products & Chemicals (APD - Get Report) traded relatively evenly.

One of the few June gainers in the Pershing portfolio was Dallas-based real estate developer Howard Hughes (HHC - Get Report) , whose shares climbed 3.5% but are down 22% over the past 12 months as of midday trading Tuesday.