Updated Wednesday, 10 December 2025 – mid‑session (approx. 2:00pm AEDT)
The Australian share market is treading water today, but beneath the flat S&P/ASX 200 headline, a cluster of healthcare, speculative miners and financials are taking heavy hits. While gold stocks and other resources names are propping up the index, stocks like Cogstate, Immuron, GQG Partners and a raft of micro‑caps feature prominently on the “biggest losers” board. [1]
Below is a look at today’s biggest percentage losers on the ASX, why they’re under pressure, and what recent forecasts and analysis say about their outlooks.
Market overview: Flat index hides sharp stock‑specific pain
By early afternoon on Wednesday, 10 December 2025, the S&P/ASX 200 was hovering around breakeven, having faded early gains. Materials are modestly higher thanks to strong gold names, while tech and rate‑sensitive sectors are feeling the weight of surging local bond yields. The 10‑year Australian government bond yield has pushed above 4.8%, its highest level since 2011, adding pressure to growth stocks and long‑duration earnings stories. [2]
A live blog from the ABC describes a “mostly flat” session shaded slightly red as investors stay cautious ahead of the US Federal Reserve’s final rate decision of the year, with Wall Street having traded sideways overnight. [3]
So while the index looks calm at first glance, today is very much a stock‑picker’s market — and for some names, it’s a rough day at the office.
Biggest percentage losers on the ASX today
MarketIndex’s real‑time “Top Losers” scan shows a familiar pattern for volatile days on the ASX: small healthcare names, speculative miners and early‑stage tech among the worst performers. [4]
Top ASX percentage losers (all stocks, price ≥ 1c, mid‑session snapshot): [5]
- Immuron (IMC) – –36.67% to $0.038 (Healthcare, ~$12m market cap; –53.7% over 12 months)
- Tusker Minerals (TSK) – –26.67% to $0.11 (Basic Materials; up ~129% over 12 months)
- Janus Electric Holdings (JNS) – –24.21% to $0.072 (Utilities / clean‑energy trucking; up ~7,100% over 12 months after relisting)
- Evergold Minerals (EG1) – –18.92% to $0.03 (Basic Materials; –57% over 12 months)
- 333D (T3D) – –18.75% to $0.039 (Industrials; +290% over 12 months)
- Hiremii (HMI) – –18.61% to $0.035 (Industrials; –36% over 12 months)
- Phoslock Environmental Technologies (PET) – –17.65% to $0.014 (Industrials; –44% over 12 months)
- Cogstate (CGS) – –16.53% to $2.10 (Healthcare; still +83% over 12 months)
Smaller names dominate the extreme end of the losers list, but one mid‑cap stands out: Cogstate, where a large profit and revenue guidance reset has triggered a wave of selling and analyst commentary.
Cogstate (CGS): Guidance cut turns into a sharp sell‑off
What happened today?
Cognitive testing specialist Cogstate dropped more than 16% intraday to around $2.10, after the company issued an update this morning that pushed expected revenue and margins for the December half lower than the market had been expecting. [6]
According to coverage from ShareCafe, Cogstate now expects first‑half (H1 FY26) revenue of US$25–26 million, which is only 5–9% growth year‑on‑year, versus prior guidance that implied growth closer to the high‑teens and consensus estimates around US$29.2 million. [7]
Gross margins are also expected to fall from roughly 61% last year to about 50–52%, and EBIT margins to 14–17% versus a previous 20–28% range, as a greater share of revenue comes from services that are recognised over the life of clinical trials rather than upfront. [8]
Why the downgrade? “Timing, not demand”
Management has framed the update as a timing issue, not a collapse in underlying demand: several contracts signed in the December half can’t yet be recognised as revenue under accounting rules, deferring income into the back half of FY26. [9]
Analysts and commentators broadly echo that message:
- Kalkine Media notes that revenue growth is now “high single digit” rather than prior elevated expectations, with margin compression driven by a shift in revenue mix and investments ahead of growth. [10]
- StocksDownUnder describes today’s sell‑off (it estimates ~22% including an early plunge) as “overstated relative to a timing mismatch,” arguing that contract backlog and expansion into new therapeutic areas support a stronger second half if execution goes to plan. [11]
Outlook and key risks
The consensus from today’s analysis is that Cogstate’s long‑term story is still intact, but the market is repricing the stock for:
- Lower certainty around near‑term earnings, and
- The risk that “timing delays” could become a recurring feature rather than a one‑off issue. [12]
If previously signed work starts to flow through as revenue in the June half and margins stabilise, there is scope for a positive re‑rating. But if delays persist or clinical‑trial activity softens, analysts warn that the downgrade could be the start of a more extended derating of this high‑multiple healthcare name. [13]
Immuron (IMC): Dilution worries and micro‑cap volatility
Immuron, a tiny biopharmaceutical company best known for Travelan, an over‑the‑counter product aimed at traveller’s diarrhoea, is today’s single biggest percentage loser, down 36.67% to 3.8 cents. [14]
Data from Intelligent Investor shows the stock is now down more than 42% over the past week and over 50% year‑on‑year, underlining how quickly sentiment can swing in micro‑cap biotech. [15]
In recent days Immuron has issued around 45.5 million new fully paid ordinary shares onto the ASX, part of previously flagged transactions to strengthen its capital base. [16] That influx of new stock has likely contributed to today’s heavy selling, as investors factor in dilution and question near‑term funding needs.
Longer‑term forecasts for the US‑listed Immuron security (IMRN) point to solid revenue growth but continued earnings losses, reflecting heavy investment and the binary nature of clinical‑stage projects. [17] Without fresh, positive clinical catalysts, price action in a name this small can be driven more by flows and sentiment than by fundamentals on any given day.
Tusker Minerals (TSK), Janus Electric (JNS) and Evergold (EG1): Hot small caps cool off
Tusker Minerals (TSK): Big swings in African minerals explorer
Tusker Minerals — an African‑focused explorer with projects in Cameroon and Malawi — is off 26.67% to 11 cents today. Yet even after that drop, the stock is still up more than 120% over the past year, highlighting how speculative the ride has been. [18]
There are no fresh, price‑sensitive ASX announcements today. The move appears to be profit‑taking and lower liquidity rather than a clear new fundamental shock, against a backdrop of higher bond yields that often weigh on early‑stage resource names. [19]
Janus Electric (JNS): Battery‑swap truck story whipsaws
Clean‑energy trucking play Janus Electric Holdings is down 24.21% to 7.2 cents, as the stock continues a volatile stretch following its reinstatement to trading on 21 November, when the ASX lifted a trading suspension after Janus lodged its delayed annual report. [20]
Janus is working on battery‑swap systems for heavy vehicles, including pilot programs for electric trucks and partnerships for battery supply. [21] With a market cap under $10 million and a business that is still proving out its commercial model, relatively small sell orders can produce outsized percentage moves.
Evergold Minerals (EG1): “Sell the news” after gold discovery
Evergold Minerals has slumped 18.92% to 3 cents, only days after releasing upbeat assay results confirming gold prospectivity at its Bynoe project in the Northern Territory. [22]
Despite the positive drilling news, the stock has been weak over the past year, and today’s move looks like a classic “sell the news” reaction in a speculative explorer: traders who bought on anticipation taking profits once the update landed, against a risk‑off backdrop for junior miners. [23]
European Lithium (EUR) and other resource names under pressure
Further down the losers list, but still notable given their profile, are European Lithium (EUR) and a host of other resource stocks.
European Lithium is trading around 18 cents, down 5.26% on the day and with more than $1.5 million in turnover, despite being up over 300% in the past 12 months thanks to enthusiasm about its Wolfsberg lithium project in Austria and its stake in Greenland’s Tanbreez rare earths project. [24]
Technical analysis site StockInvest has been flagging EUR as a short‑term “sell candidate” since earlier this week, citing recent price weakness after a strong run, while still acknowledging the longer‑term uptrend. [25] Today’s move fits that narrative: a stock with big gains in the rear‑view mirror proving highly sensitive to swings in lithium and rare‑earth sentiment.
Other materials names on the losers screen — from niche explorers to graphite, vanadium and gold juniors — underscore a broad theme: 2025’s resource high‑flyers are seeing heavier profit‑taking on days when macro news (like the Fed) encourages investors to de‑risk. [26]
ASX 200 losers: GQG, Iluka, Pro Medicus and Lynas are feeling the heat
Within the S&P/ASX 200, today’s worst‑performing names are much larger and more widely held than the micro‑caps at the top of the losers table. Mid‑session, MarketIndex’s ASX 200 live blog showed the following among the weakest blue chips: [27]
- Iluka Resources (ILU) – around –3% to –4% on the day, extending a multi‑session slide and leaving the stock down nearly 8% over the past 10 days. [28]
- Reece (REH) – roughly –3%, continuing a difficult 18‑month stretch as plumbing and building products demand slows and US operations underperform. [29]
- Pro Medicus (PME) – down about 4–5% intraday to the mid‑$230s, with data from Investing.com showing a 4.6% decline for the session and a near‑9% fall over the last week. [30]
- GQG Partners (GQG) – off around 5% at one point and still down ~3% in MarketIndex’s midday snapshot, making it the worst‑performing ASX 200 stock at the open. [31]
- Lynas Rare Earths (LYC) – modestly lower today after already falling about 5% in yesterday’s session, when it topped the blue‑chip losers list as rare‑earths sentiment cooled. [32]
GQG Partners: Flows turn negative
Fund manager GQG Partners is under pressure after its latest fund‑under‑management (FUM) update showed net outflows of 2.4% in November, leaving flows down 1.8% year‑to‑date despite rising markets. Total FUM still increased to US$166.1 billion, up from US$163.7 billion in October, thanks to investment performance. [33]
Capital Brief notes that the stock was “among the worst performing” in early trade, with the market clearly focused on the negative flows rather than the headline FUM growth. [34] Analysts have previously highlighted GQG’s high payout ratio and double‑digit yield as both an attraction and a vulnerability: generous dividends depend on sustained inflows in a competitive global asset‑management landscape. [35]
Iluka, Lynas and the critical minerals complex
For Iluka and Lynas, today’s weakness extends a broader consolidation across critical minerals. Iluka has been drifting lower throughout December after a patchy few months of production updates and ongoing uncertainty around tariffs and the outlook for zircon and rare‑earth pricing. [36]
Lynas, meanwhile, has absorbed a $750 million equity raise and complex news flow around licensing and US‑Australia strategic supply deals. Analysts warn that, after tripling in value earlier in 2025 and being promoted to the S&P/ASX 50, the bar for further upside has risen sharply — making the stock more vulnerable to corrections on days when risk appetite wanes.
Pro Medicus: High expectations meet a wobbly tape
Even without fresh stock‑specific bad news today, Pro Medicus is finding that living up to its sky‑high valuation is no easy feat. After a parabolic run that took 12‑month gains to nearly 200%, PME has been giving back ground over recent weeks.
The company continues to deliver strong revenue growth from its radiology imaging software platform, but with the stock priced for perfection, any whiff of broader tech or rate jitters can trigger a pullback – exactly the kind of environment today’s rising yield backdrop provides. [37]
How today’s losers fit into the bigger picture
A few common threads run through today’s biggest ASX losers:
- High expectations meeting reality
- Cogstate and Pro Medicus have been priced for strong, consistent growth. When guidance or market conditions challenge that smooth trajectory, the sell‑off is amplified. [38]
- Speculative micro‑caps magnifying every headline
- Immuron, Tusker, Janus and Evergold all have small market caps and limited liquidity, so new shares being issued, a change in risk appetite, or simple profit‑taking can swing prices 20–30% in a single session. [39]
- Macro headwinds for long‑duration and growth assets
- Bond yields near cycle highs and an imminent Fed decision are reinforcing a risk‑off tone around growth, tech and highly valued “story stocks”, while gold and silver miners outperform. [40]
- Critical minerals volatility
- Stocks tied to lithium and rare earths (European Lithium, Lynas, Iluka, Lindian and others) are seeing bigger swings as investors constantly re‑price long‑dated projects against changing commodity price and geopolitical assumptions. [41]
What investors should watch next
For readers tracking today’s biggest losers, the next few days and weeks will be key to distinguishing one‑day noise from enduring trend:
- Cogstate (CGS) – Watch for any follow‑up commentary from brokers, and for signs in the next quarterly that deferred revenue does indeed show up in the second half, with margins stabilising. [42]
- Immuron (IMC) – Monitor further capital‑raising activity, clinical trial milestones and whether liquidity and price stabilise after the latest batch of new shares beds down. [43]
- GQG Partners (GQG) – Monthly FUM releases will be closely watched to see whether November’s outflows were a blip or the start of a more persistent trend. [44]
- Critical minerals names (LYC, ILU, EUR, LIN, etc.) – Sector sentiment could swing quickly on commodity price moves, new offtake deals, or changes in government policy around strategic minerals. [45]
References
1. www.marketindex.com.au, 2. www.marketindex.com.au, 3. www.capitalbrief.com, 4. www.marketindex.com.au, 5. www.marketindex.com.au, 6. markets.ft.com, 7. www.sharecafe.com.au, 8. kalkinemedia.com, 9. kalkinemedia.com, 10. kalkinemedia.com, 11. stocksdownunder.com, 12. kalkinemedia.com, 13. kalkinemedia.com, 14. www.morningstar.com.au, 15. www.intelligentinvestor.com.au, 16. www.tipranks.com, 17. simplywall.st, 18. www.morningstar.com.au, 19. www.marketindex.com.au, 20. www.intelligentinvestor.com.au, 21. smallcaps.com.au, 22. discoveryalert.com.au, 23. www.morningstar.com.au, 24. www.investing.com, 25. stockinvest.us, 26. www.marketindex.com.au, 27. www.marketindex.com.au, 28. www.marketindex.com.au, 29. www.marketindex.com.au, 30. www.marketindex.com.au, 31. www.marketindex.com.au, 32. www.marketindex.com.au, 33. www.capitalbrief.com, 34. www.capitalbrief.com, 35. kalkinemedia.com, 36. www.marketindex.com.au, 37. www.marketindex.com.au, 38. stocksdownunder.com, 39. www.tipranks.com, 40. www.marketindex.com.au, 41. www.proactiveinvestors.com, 42. www.sharecafe.com.au, 43. www.tipranks.com, 44. www.capitalbrief.com, 45. www.investing.com
