Short Report: Bears focus on crypto space, boost bets on CleanSpark, Mara

Welcome to this week’s installment of “The Short Interest Report” – The Fly’s weekly recap of short interest trends among some of the most widely followed high-short-float stocks. Using the data from our partner Ortex.com, which utilizes the latest information from stock lenders to estimate short interest changes for thousands of publicly traded companies, this report will screen for some of biggest changes in short interest as a percentage of free float and days-to-cover ratios while also considering the short interest data on some of the more volatile and heavier-traded names of the week. Based on the availability of data from Ortex, the report tracks the trading period that covers prior Friday through Thursday of this week, excluding holidays. As a basis of comparison for stocks discussed below, the S&P 500 index was up 0.5%, the Nasdaq Composite was up 0.6%, the Russell 2000 index was down 0.1%, the Russell 2000 Growth ETF (IWO) was down 0.4%, and the Russell 2000 Value ETF (IWN) was flat in the five-day trading session range through March 27.

SHORT INTEREST GAINERS

• Ortex-estimated short interest in CleanSpark (CLSK) jumped six percentage points from 29% to 35% and days to cover on the name spiked from 5.3 to 7.2 – both record highs. The stock received an 18% bump on Monday when its inclusion in the S&P SmallCap600 index went into effect and reflecting last weekend’s bitcoin rally, though with a broader downdraft remaining entrenched in the cryptocurrency space, bears faded nearly all of that move over the next three sessions. In the five-day period covered, shares of CleanSpark shares were up 2.4%, though year-to-date, and inclusive of Friday’s 8% drop, the stock is off by 22%.
• Ortex-reported short interest in Mara Holdings (MARA) tracked CleanSpark flows to the tee – early week strength in the stock price was faded over the next sessions with higher bearish involvement and a flush on Friday. Shorts as a percentage of free float on Mara rose from about 26% to 29.5% by Thursday – a six-month high – while Monday’s 18% stock price jump that followed bitcoin’s near $4,000 gain last weekend was reversed over the balance of the week. Shares of Mara were also higher in the five-day period through Thursday – up 9% – but Friday’s 8.6% decline has now seen the stock lose 25.6% overall in 2025.
• Rising short interest against sideways stock price action – a pattern we described in Quantum Computing (QUBT) last week – has played out this week with its quantum computing relative Rigetti Computing (RGTI). Shorts as a percentage of free float in Rigetti rose from about 22% to over 25% – a record high – and days to cover on the name increased to 1.0 from 0.8. Meanwhile, shares of Rigetti were down about 6% in the five-day period through Thursday, and inclusive of Friday’s 3.8% decline, the stock has now fallen 47% year-to-date.
• Ortex-reported short interest in Dianthus Therapeutics (DNTH) troughed at a six-month low of 31% last Thursday before jumping seven percentage points to 38%. Most of the increase came late in the week after the stock fell to a multi-month low on Wednesday, with bears selling into the stock’s bounce. In the five-day period covered through Thursday, shares were down 2.8%, and year-to-date, the stock has fallen 8.3%.
• Shares of EVgo (EVGO) are up 28% in just over three weeks from early March lows, but after a pause for much of the month, bears have renewed accumulating activity this week. Ortex-estimated shorts as a percentage of free float on EVgo was up from 28.2% to 32.2% while days-to-cover on the stock rose from 4.2 to 4.7 – a four-month high. Concern over federal funding for EV charging infrastructure has hung over the sector since the election – shares are down 62% since November 5 and down 30% year-to-date, though in the five-day period covered this week, EVgo was up 5.5%.

SHORT INTEREST DECLINERS

• Ortex-reported short interest in Celsius Holdings (CELH) was down sharply this week, falling from 21.0% to 15.8%, the lowest level since mid-November, while days to cover on the name slipped from 4.1 to 3.5 – a seven-month low. The energy drink company has been out of favor since May of last year, losing about 80% of its value from the highs on worries over inventory destocking by Pepsi (PEP), though stronger than expected Q4 results reported last month and the acquisition of Alani Nu have given the stock a jolt, dispelling demand concerns. Shares are up 32% from the reporting and acquisition announcement date and also up 28% year-to-date, driving shorts to the sidelines, with the stock also up 12% in the five-day period covered this week.