Top Stock Movers Today — August 3, 2026: Why HYFM, FUSE, LUNG, SDST & ATKR Surged
Hydrofarm Holdings, Fusemachines, Pulmonx, Stardust Power, and Atkore were the biggest stock gainers today, August 3, 2026. Here's what drove each move.
HYFM — Hydrofarm Holdings Group (+303.7%)
Hydrofarm Holdings closed up 303.7% to $2.18 on volume of 54,017,616 shares — roughly 20× its 20-day average of 2,739,315. For a company with a market cap of just $2.6 million, that kind of volume is extraordinary and signals a near-total reshaping of the stock's short-term ownership.
Why it moved: According to a Yahoo Finance report published August 3, Hydrofarm completed the sale of its Aurora Peat Products business and simultaneously announced "Project Agility," a strategic initiative to scale its logistics services platform. That combination — a completed asset sale plus a forward-looking restructuring plan — appears to have been the ignition point for today's explosive move.
On the technical side, HYFM's gap open was a staggering +475.0% at the intraday peak before settling into a +303.7% close-to-close gain. The RSI hit 86, deep into overbought territory, and the ADX of 31 confirms a strong short-term trend in force. The StockSetups conviction score sits at 42/100 with a grade of D — a reminder that the technical structure here is fragile. The stock remains 53.1% below its 52-week high even after today's surge, underscoring just how beaten-down it was coming in. A delisting-related 8-K was filed on July 9, which means shareholders were already navigating serious compliance risk. Treat this one with extreme caution — triple-digit one-day moves in micro-caps almost always come with severe whipsaw risk.
FUSE — Fusemachines Inc. (+67.1%)
Fusemachines, an AI technology company, closed up 67.1% to $1.31 on volume of 73,665,240 shares — nearly 20× its 20-day average of 3,730,293. The market cap stands at just $23.0 million, putting this firmly in micro-cap, high-risk territory.
Why it moved: No company-specific news headline was on file for today's session, and no clearly bullish SEC filing accompanied the move. What is on file is a delisting-related 8-K filed July 24 — a bearish structural signal that indicates Fusemachines has been under exchange compliance pressure. With no confirmed catalyst, today's move looks primarily momentum- and technically-driven, potentially amplified by low-float dynamics and speculative interest.
The float dynamic matters here: with a $23 million market cap and volume exceeding 73 million shares traded, turnover was enormous relative to the company's size — the hallmark of a low-float squeeze. A low float means relatively few shares are available for trading; when buying volume spikes, prices can move violently in either direction. The ADX of 53 confirms a powerful short-term directional move, and RSI at 70 puts the stock at the edge of overbought. The gap of +21.2% at the open set the aggressive tone. StockSetups' conviction score of 43/100 (grade D) and the looming delisting risk mean this is a name for very experienced, risk-tolerant traders only.
LUNG — Pulmonx Corp (+29.4%)
Pulmonx Corp, a healthcare company focused on minimally invasive bronchoscopic treatments, closed up 29.4% to $2.11 on volume of 6,611,473 shares — approximately 7.8× its 20-day average of 844,743. The market cap is $68.4 million.
Why it moved: No company-specific news headline was on file for August 3. However, Pulmonx filed an earnings-related 8-K on July 29, as well as a Schedule 13G/A disclosing a stake change. Today's move may reflect a delayed or continued market reaction to that earnings report, combined with renewed institutional interest signaled by the stake-change filing. Without a confirmed same-day catalyst, the precise trigger remains somewhat unclear — but the combination of elevated volume and recent fundamental filings provides context.
From a technical standpoint, LUNG is one of the stronger setups in today's mover list. The StockSetups conviction score is 77/100 with a grade of A — the highest-quality read among today's gainers. The trend-template score of 5 indicates the stock is aligning with several key Minervini trend-template criteria (a framework that checks whether a stock's price and moving averages are properly stacked for an uptrend). RSI at 77 is elevated but not at an extreme, and ADX at 26 shows a developing trend. The RS rating of 88 means LUNG has been outperforming 88% of all stocks in the StockSetups universe over the recent period. Smart-money signals show the largest disclosed institutional stake at 1.8% — modest, but worth noting alongside the 13G/A filing.
SDST — Stardust Power Inc. (+28.9%)
Stardust Power, an industrial-sector micro-cap, closed up 28.9% to $0.70 on volume of 7,484,886 shares — nearly 10× its 20-day average of 752,983. The market cap is just $5.7 million, and the stock sits a painful 90.2% below its 52-week high — meaning today's bounce, while sharp, barely makes a dent in the longer-term drawdown.
Why it moved: No news headline or clearly bullish filing was on file for August 3. A management-related 8-K was filed July 24, but it is marked neutral and offers no obvious bullish signal. With no confirmed catalyst, today's move appears to be technically and momentum-driven — a sharp bounce in a severely oversold name that may have attracted speculative interest.
The candlestick reading is telling: StockSetups flagged an inverted hammer formation. An inverted hammer appears after a downtrend and features a small body with a long upper wick — it can signal a potential reversal attempt, but requires confirmation on subsequent days. Despite the day's gain, the RSI of 26 remains in oversold territory (below 30), and the MA stack is bearish, meaning the moving averages are not yet aligned for an uptrend. The conviction score of 24/100 with a grade of D and a trend-template score of just 1 make this one of the weakest structural setups in today's group. An extreme single-day bounce in a stock 90% off its highs is often a "dead-cat bounce" — a brief recovery within a larger downtrend — rather than a genuine reversal.
ATKR — Atkore Inc. (+28.1%)
Atkore Inc., a manufacturer of electrical raceway products and mechanical products and solutions, closed up 28.1% to $93.49 on volume of 11,638,672 shares — about 12.8× its 20-day average of 912,125. With a market cap of $2.5 billion, this is by far the largest, most liquid name in today's mover list.
Why it moved: Atkore had a double catalyst that lit the fuse. First, the company reported Q3 earnings that beat both profit and revenue estimates, as confirmed by multiple sources including Yahoo Finance and Benzinga. Second — and arguably bigger — Atkore agreed to be acquired by Italian cable giant Prysmian in a deal valued at $3.8 billion, at $95 per share, according to reporting from Yahoo Finance and Advfn. An all-cash acquisition at a premium to the prior close is one of the most straightforward drivers of a gap-up in equities; buyers immediately push the stock toward (but typically not fully to) the deal price to account for deal-risk and time value. At $93.49, the market is pricing in a small spread below the $95 offer — consistent with normal merger-arbitrage dynamics.
The technical picture is notably clean for a gapper of this magnitude. ATKR closed at a 52-week high, the MA stack is bullish (shorter-term moving averages above longer-term ones), RSI is 73 (elevated but not at an extreme for a confirmed-news breakout), and the trend-template score of 7 is the highest of today's five movers. StockSetups' conviction score is 69/100 with a grade of B. That said, with the stock already pricing in most of the $95 deal premium, the asymmetric upside from here is limited unless a competing bid emerges — which is purely speculative.
The bottom line
Today's five biggest gainers ranged from a $2.6 million micro-cap up 304% on a restructuring announcement, to a $2.5 billion industrial up 28% on a blockbuster acquisition deal. That diversity is a reminder of how many different forces can produce a big single-day move — asset sales, momentum, earnings beats, and M&A all showed up in one session.
The risk reminder is important: chasing stocks after moves of this magnitude is one of the most dangerous things a trader can do. Many of the biggest single-day gainers in small- and micro-cap names give back a significant portion of their gains in the days that follow. Micro-caps near delisting (HYFM, FUSE), stocks 90% off their highs (SDST), and names at RSI extremes deserve especially hard scrutiny. Even the cleanest setup here (LUNG, ATKR) carries meaningful post-surge risk. Chart patterns and squeeze signals increase the probability of a move — they do not guarantee it. Manage your position size, use stop-losses, and always do your own research before trading any of these names.
This is not financial advice or a recommendation to buy or sell any security.
StockSetups scans the full ~12,300-stock US universe after every close, detecting confirmed chart patterns, computing conviction and short-squeeze scores, and sorting actionable setups into four ranked lanes — so you can see which names are genuinely setting up versus simply making noise. Check back after tomorrow's close for the next recap, and browse our recent recaps for more context on the market's daily movers:
Frequently asked questions
Why is HYFM stock up today?
Hydrofarm Holdings (HYFM) surged 303.7% on August 3, 2026, after the company announced it completed the sale of its Aurora Peat Products business and launched Project Agility, a plan to scale its logistics services platform. The stock also benefited from extremely high volume relative to its tiny float.
Why is ATKR stock up today?
Atkore (ATKR) jumped 28.1% on August 3, 2026, on two simultaneous catalysts: Q3 earnings that beat both profit and revenue estimates, and an announcement that Italian cable manufacturer Prysmian agreed to acquire the company for $95 per share in a deal valued at approximately $3.8 billion.
Why is FUSE stock up today?
Fusemachines (FUSE) rose 67.1% on August 3, 2026, with no confirmed news catalyst on file. The move appears technically and momentum-driven, amplified by the stock's very low market cap ($23M) and turnover that was roughly 20× the 20-day average volume. Note that a delisting-related 8-K was filed in late July, making this a high-risk situation.
What is a low-float short squeeze?
A low float means a stock has relatively few shares available for public trading. When buying demand spikes suddenly — from news, momentum, or social media — there aren't many shares to absorb that demand, so prices can move dramatically higher in a short time. If short sellers (who bet the price falls) are also caught in the move, they must buy shares to close their positions, adding more buying pressure. This chain reaction is called a short squeeze. Low-float squeezes can reverse just as violently.
What does the StockSetups conviction score mean?
The StockSetups conviction score is a 0–100 rating that reflects how well a stock's technical setup aligns with the platform's criteria for a high-quality trade candidate. A higher score means stronger technical alignment; a lower score (like the D-grade names in today's recap) signals a weaker or riskier setup despite a large price move.
Produced with AI assistance and published under the StockSetups editorial guidelines.
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