Regencell Bioscience (RGC) Stock Jumps Over 20% on December 4, 2025 as DOJ Probe and Going‑Concern Warning Shadow 2025’s Wildest Rally

Regencell Bioscience Holdings Limited (NASDAQ: RGC) is back on traders’ radar. On Thursday, December 4, 2025, RGC shares surged more than 20% intraday, trading in the mid‑teens after yet another volatile session in what has arguably been 2025’s most extreme stock story. Intraday data from several market trackers showed the stock changing hands around $16–17, up roughly 24–31% on the day, with the price swinging between about $13 and over $18 on volume close to 1 million shares. ^[1]

That move comes on the back of a year in which RGC has:

Rallied from pennies to tens of dollars, with a 52‑week range of roughly $0.08–$83.60. TS2 Tech+2INDmoney+2
Briefly sported a market value north of $30–40 billion at its peak despite reporting no revenue and sustained losses. ^[2]
Disclosed a “substantial doubt” about its ability to continue as a going concern and received a U.S. Department of Justice (DOJ) subpoena related to trading in its shares. ^[3]

Below is a detailed look at today’s move, the underlying business, this year’s extraordinary price action, and the latest forecasts and risk assessments surrounding RGC stock.

RGC stock news today: what is driving the December 4, 2025 surge?

As of Thursday afternoon, multiple real‑time feeds pegged RGC up around 23–30%, trading near $16–17 per share. ^[4]

Key intraday details:

Price range today: roughly $13.1 – $18.1. ^[5]
Recent close (prior session): around $13.0. ^[6]
52‑week range: about $0.09 at the low to $83.60 at the high, set in June 2025. ^[7]

Today’s spike does not appear to be driven by fresh company‑specific press releases. Instead, the move looks like a classic continuation of the momentum and speculative trading that have defined RGC in 2025:

Screeners tracking “stocks in motion” flagged RGC as one of the top percentage gainers, noting an intraday jump of about 31% to over $17. ^[8]
GuruFocus framed Thursday’s action as a 23–24% surge to roughly $16.09, citing “strong upward momentum” rather than a new clinical or financial catalyst. ^[9]

Given the company’s limited float, heavy insider ownership, and history of extreme volatility, relatively modest order flow can translate into outsized price swings. ^[10]

What does Regencell Bioscience (RGC) actually do?

Behind the roller‑coaster chart is a very small, early‑stage biotech:

Headquarters: Hong Kong
Listing: Nasdaq Capital Market, ticker RGC
Business focus: research and development of Traditional Chinese Medicine (TCM)‑based treatments for neurocognitive disorders, particularly ADHD (attention‑deficit/hyperactivity disorder) and ASD (autism spectrum disorder), as well as a COVID‑19‑related formulation. ^[11]

Key points about the pipeline and strategy:

The company is working on standardized liquid TCM formulae targeting mild, moderate and severe ADHD/ASD initially in Hong Kong, with longer‑term ambitions to expand to other markets. ^[12]
Earlier efficacy trials (personalized and standardized formulae) showed improvements in ADHD and ASD symptom scores based on widely used rating scales such as VADRS and ATEC, with no serious adverse side effects reported in interim analyses. ^[13]
Regencell’s mission, as stated on its site, is to “save and improve lives” using TCM for children with ADHD/ASD and elderly patients with dementia, supported by a charitable foundation. ^[14]

In September–October 2025, the stock also gained a degree of institutional visibility when Regencell was added to the S&P Global BMI Index following positive ADHD/ASD trial news, a move that can marginally improve liquidity by making the name eligible for some index‑linked strategies. ^[15]

2025 in review: from penny stock to 80,000% rally and back

RGC’s 2025 performance has attracted global headlines for its sheer extremity.

A bizarre multi‑thousand‑percent surge

Various outlets have documented how RGC rocketed from around $0.08–0.10 early in the year to tens or even hundreds of dollars within months. MarketBeat+3TS2 Tech+3The Motley Fool+3
Bloomberg described Regencell as an “herbal medicine stock with no sales” whose rally topped 64,000% at one point. ^[16]
An RTTNews report highlighted a jump from about $4 to $470 in roughly two months in the spring. ^[17]
By mid‑year, Yahoo Finance was running articles about an 82,000% surge and a $33–42 billion paper fortune tied to the company’s founder as the stock’s market cap briefly exploded. ^[18]

Several post‑mortems put the move down to a cocktail of:

Extremely small free float (around 6% of shares freely tradable) with ~80–90% insider ownership, especially by the CEO. ^[19]
Retail‑driven speculation, particularly in Asian and U.S. retail trading communities. ^[20]
AI‑driven and algorithmic trading amplifying price momentum, as detailed in long‑form analyses of the stock’s 2025 surge. ^[21]

The 38‑for‑1 stock split and volatility halts

A major turning point came in June 2025, when Regencell executed a 38‑for‑1 forward stock split:

The company announced the split on June 2, 2025, stating it wanted to improve liquidity and accessibility. ^[22]
When the split took effect around June 13, the post‑split shares more than quadrupled on the first day of trading, according to Investopedia. ^[23]
Bloomberg and other outlets noted that the split and thin float helped propel RGC to one of the most extreme rallies ever seen on Nasdaq. ^[24]

Regulators’ volatility controls also came into play:

Trading in RGC was repeatedly paused due to limit‑up/limit‑down mechanisms as daily swings of several hundred percent became common. ^[25]
Financial press headlines chronicled a sequence of double‑digit percentage jumps and crashes throughout July and August. ^[26]

By late 2025, the share price had retreated from triple‑digit levels to the mid‑teens — still up tens of thousands of percent from its 52‑week low but down 70–80% from its peak. ^[27]

Fundamentals and financial results: still a pre‑revenue biotech

Despite the spectacular stock moves, Regencell remains pre‑revenue and loss‑making.

Earnings and losses

For the half‑year ended December 31, 2024, Regencell reported a net loss of about US$1.85 million, slightly improved from US$2.07 million a year earlier. ^[28]
In its annual report on Form 20‑F filed on October 31, 2025, the company disclosed net losses of US$3.58 million in fiscal 2025 and US$4.36 million in fiscal 2024, again with no operating revenue. ^[29]

Most importantly, the company’s independent auditor, Marcum LLP, included a going‑concern warning:

There is “substantial doubt” about Regencell’s ability to continue as a going concern unless it secures additional financing or begins generating sufficient revenue. ^[30]

Analyses from sites like Biyapay and Finimize emphasize that:

Regencell has no commercial products,
relies on equity funding and cash reserves, and
trades at valuations that appear detached from its current asset base and earnings. ^[31]

Legal and regulatory clouds: DOJ subpoena and shareholder investigations

The speculative run in RGC has now attracted regulatory and legal scrutiny.

DOJ investigation into trading

On October 31, 2025, Regencell disclosed that it had received a subpoena from the U.S. Department of Justice:

The DOJ requested documents and communications relating to trading in the company’s ordinary shares, as well as other operational, financial and accounting matters, according to the company’s SEC filing and subsequent media reports. ^[32]
Bloomberg and other outlets have framed the probe as part of a broader investigation into the unprecedented 40,000–60,000% surge in Regencell’s stock price earlier this year. ^[33]

A TipRanks report noted that the investigation has already weighed on the stock and could lead to significant legal costs and potential fines or penalties. ^[34]

Shareholder law firm activity

Following the 20‑F and DOJ disclosure:

Investor‑rights firm Bragar Eagel & Squire announced it is investigating Regencell for potential securities law violations, citing the DOJ probe and the company’s own warnings about possible fines and elevated legal costs. ^[35]
Other law firms, including Pomerantz LLP (referenced in Simply Wall St / Webull coverage), have launched similar investigations. ^[36]

These legal overhangs mean that regulatory risk is now a central part of the RGC investment story, alongside the usual clinical and commercialization risks faced by early‑stage biotech firms.

RGC stock forecasts and analyst views as of December 4, 2025

Despite the massive attention the stock has received, formal Wall Street coverage remains sparse, and what does exist is extremely cautious.

Traditional analyst coverage: “Sell” with implied 100% downside

MarketBeat’s latest compilation shows:

Number of Wall Street analysts: 1
Consensus rating:Sell (classified as “Strong Sell” in their scoring system).
12‑month forecast: effectively –100% implied downside, reflecting the analyst’s view that shares could ultimately be worth close to zero. ^[37]

That rating comes from Weiss Ratings, which reiterated a Sell (E+) on December 1, 2025, underscoring concern about valuation, risk profile and the going‑concern language. ^[38]

Quant and technical models: mixed, often optimistic

In contrast to the lone human analyst, several quantitative/technical services are more constructive on the stock — at least over the short term:

StockScan.io lists an average 12‑month price target of about $14.83, implying ~9% downside from the mid‑$16s, and characterizes the near‑term technical picture as “Buy” based on moving averages and oscillators. ^[39]
Intellectia.ai’s algorithmic model, updated for the current price action, forecasts:
- 1‑day move: –6.18% to about $12.21
- 1‑week: –9.37% to $11.70
- 1‑month: roughly flat at $12.97
- 2026: around $17.51
- 2030: around $20.97
  and labels RGC a “Strong Buy candidate” based on its technical signals and recent uptrend. ^[40]
StockInvest.us similarly flags RGC as a short‑term “buy candidate”, noting positive trend indicators but also highlighting prior episodes where the stock appeared severely overbought, such as when it traded over $400 in May. ^[41]

These systems are mostly price‑ and pattern‑driven, not fundamental. In other words, they tend to extrapolate from recent momentum and volatility, whereas the lone human analyst is focusing primarily on valuation, fundamentals and risk.

Fundamental commentators: “bubble” risk and overvaluation

A number of long‑form analyses published over the last few months paint a starkly different picture:

A Seeking Alpha article in September argued that even after an 80% drop from the peak, RGC remained “wildly overvalued” given its lack of revenue and early stage of development. ^[42]
A detailed breakdown on Biyapay concluded that the 59,000%+ 2025 surge was driven largely by speculation, the stock split and AI trading, not business progress, and emphasized the company’s zero revenue, ongoing losses and small free float as major risk factors. ^[43]
Finimize summarized the story as: “Regencell’s stock went wild, but revenue’s still elusive”, underscoring the gap between the share price and the underlying business. ^[44]

The net effect is a huge dispersion of views:

Human, fundamentals‑focused analysts and commentators skew strongly negative,
Momentum and AI‑driven models lean bullish in the short term, and
The market itself continues to swing violently as speculative traders and skeptics clash.

Key risks for RGC stock investors

Anyone considering RGC — or simply trying to understand why it behaves the way it does — should be aware of the main risk themes highlighted across filings and independent research.

Going‑concern warning and lack of revenue
- The company’s own 20‑F stresses substantial doubt about its ability to continue operating without additional funding. ^[45]
- Regencell has no commercial revenue and has “only completed the preliminary stages of [its] business plan.” ^[46]
Legal and regulatory uncertainty (DOJ probe)
- The DOJ subpoena into trading in the shares introduces the possibility of fines, penalties, or other enforcement actions, with the company itself warning that such costs may exceed any insurance coverage. ^[47]
Extreme volatility, thin float and liquidity risk
- With only a small fraction of the stock freely tradable and very high insider ownership, relatively small trades can move the price dramatically. ^[48]
- Volatility halts, large intraday swings and wide bid–ask spreads are common and can make it difficult for investors to enter or exit positions at expected prices. ^[49]
Clinical and regulatory approval risk
- Regencell’s TCM‑based therapies still need to navigate regulatory pathways, including more extensive trials and potential interactions with the U.S. FDA and other agencies. ^[50]
Valuation risk
- Even after dropping sharply from its peak, the company’s market capitalization remains far above what traditional valuation models would justify for a pre‑revenue biotech with small absolute losses. ^[51]

Should you buy RGC stock after the latest spike?

From a news and analysis standpoint, December 4, 2025 finds RGC at a crossroads:

Bullish arguments lean heavily on:
- Strong trial signals in ADHD/ASD,
- Index inclusion (S&P Global BMI),
- Improved though still negative earnings, and
- The potential for TCM‑based neurocognitive therapies to gain broader acceptance. ^[52]
Bearish arguments emphasize:
- The going‑concern warning,
- The DOJ investigation and law‑firm probes,
- Persistent lack of revenue, and
- A valuation history that has swung from implausibly high to merely very speculative. ^[53]

Where does that leave today’s buyer?

From a traditional, fundamentals‑driven perspective, the lone Wall Street analyst’s “Sell” rating and implied 100% downside reflect the view that the risk of permanent capital loss is very high. ^[54]
From a short‑term trading perspective, quant and technical services see RGC as a high‑volatility vehicle that can continue to offer large moves in either direction — but those same services routinely stress the need for strict risk management. ^[55]

Nothing in this article is financial advice. RGC is a highly speculative stock whose price is being driven by a complex mix of thin liquidity, momentum trading, regulatory headlines and hopes around a still‑developing TCM pipeline. Anyone considering exposure should:

Read the company’s latest 20‑F filing and risk factors in full,
Understand that they could face rapid and total loss of capital, and
Size any position accordingly, if they choose to participate at all. ^[56]

For market observers, regardless of investment stance, Regencell remains a live case study in how pre‑revenue micro‑caps, algorithmic trading and regulatory scrutiny can collide to produce one of the wildest stock stories of 2025.