Biggest Small-Cap Gaps 2026-08-18: Float and Dilution Sourced

Direct answer: Seven small-caps gapped violently on 2026-08-18: PFSA (Profusa, Inc.) peaked at +597% intraday on a 0.53 million share float, XOS (Xos, Inc.) at +156% on 14.22 million float, SLE (Super League Enterprise, Inc.) at +127% on 1.61 million, and SGLY (Singularity Future Technology Ltd.) at +111% on 0.90 million. These moves illustrate the mechanical relationship between tight float, concentrated volume and extreme volatility, all measurable in SEC filings.

Top movers: PFSA, XOS and SLE

PFSA (Profusa, Inc.) posted the session's most spectacular intraday peak: +597% from the prior close. The opening gap stood at +95%. The stock then ran to a high of $26.81. Float measured at the time of the move was 0.53 million shares, while the day's volume totaled 40,186,013 shares traded—roughly 76 times the float.

This extreme volume-to-float ratio means every available share changed hands, on average, more than seventy times during the day. On a gapping small-cap, this rapid rotation mechanically creates outsized volatility: the slightest buying or selling pressure immediately impacts price in the absence of natural counterparties.

XOS (Xos, Inc.) rounds out the podium with an intraday peak of +156% and an opening gap of +117%. Price touched $4.48 at the high. The 14.22 million share float is significantly wider than PFSA's, but volume of 50,058,184 shares remains very high—roughly 3.5 times the float. This lower ratio explains a less explosive but still violent move.

SLE (Super League Enterprise, Inc.) ran to +127% intraday, with an opening gap of +106% and price topping out at $5.25. Measured float: 1.61 million shares. Volume: 26,543,428 shares, roughly 16.5 times the float. Same mechanism. A tight float facing concentrated volume generates asymmetric volatility, both up and down.

Other notable movers: SGLY, IVF, RCON and VSME

SGLY (Singularity Future Technology Ltd.) peaked at +111% intraday—a +50% opening gap, price at $3.5099. Float: 0.90 million shares. This is a micro-cap by free float market cap. Volume: 4,102,863 shares (roughly 4.6 times the float), more modest than the top three, but enough to trigger a violent move on such a narrow base.

IVF (INVO Fertility, Inc.) jumped +79% intraday, after an opening gap of +133%. The opening price was already 2.33 times the prior close. High at $1.53. Measured float: 1.79 million shares. Volume: 2,290,783 shares, roughly 1.3 times the float. The extreme opening gap—larger than the intraday peak—suggests an event occurred before the bell. The move then faded during the session.

RCON (Recon Technology, Ltd.) presents the session's most puzzling gap: +18,873% at the open. Such a percentage mathematically indicates the prior close was near zero—on the order of a few tenths of a cent—followed by an opening around $3.30 or close to that level. The intraday peak was only +42% from this new reference point.

Float: 90.63 million shares, the widest on this list. Volume: 1,018,791 shares (roughly 0.01 times the float), very light. This suggests a technical correction or quote adjustment rather than massive volume influx. Without additional context, it's impossible to attribute a specific cause to this extreme gap. It does illustrate the importance of checking historical context—reverse splits, extended halts, resumption of trading—before characterizing an isolated percentage.

VSME (VS Media Holdings Limited) posted a more modest move: +29% intraday, +46% opening gap, price at $1.22. Float: 2.78 million shares. Volume: 135,520 shares (roughly 0.05 times the float). A low-liquidity move. A handful of buy orders suffice to spike price in the absence of selling counterparties.

Float, volume and dilution: measurable mechanics

Float—or free float—represents the number of shares actually available for trading on the open market. It's obtained by subtracting from total outstanding shares the blocks held by insiders (officers, founders, control shareholders) and locked or sale-restricted institutional positions.

This information lives in SEC forms. The 10-K or 10-Q gives total outstanding shares. Schedule 13D and 13G detail positions above 5%. Form 4 tracks insider transactions in near real-time.

Float is not a fixed number. Every dilution event—capital raise (offering), warrant conversion, option exercise, RSU vesting—adds shares to the market and increases float. Conversely, a share buyback or expiration of lockup without actual sales can reduce it. This is why the measurement date matters: a 0.53 million share float for PFSA is valid at time T, but can double in days if the company raises capital.

The volume-to-float ratio quantifies mechanical price pressure. When volume represents multiples of the float—76 times for PFSA, 16.5 times for SLE—it means every available share changed hands multiple times during the day. In a market where supply and demand don't balance instantly, this rapid rotation generates violent price dislocations. Buyers "chase" sellers upward, or vice versa downward. The tighter the float, the more this mechanic amplifies.

Short Sale Restriction (SSR) and selling pressure

Regulation SHO Rule 201, the "alternative uptick rule," imposes a short sale restriction (SSR) once a stock drops 10% or more from the prior close. Once triggered, SSR prohibits "aggressive" shorts—selling at or below the bid—through the end of the following day. Short sellers can then only short at the ask or above, which slows selling pressure.

On stocks that gap violently upward then retrace during the session, SSR can trigger intraday if the drop from peak reaches 10% relative to the prior close. Example: PFSA closes at $4 the day before, gaps to $7.80 (+95%), then falls below $3.60 (-10% from $4). SSR activates for the rest of the day and the next. This rule limits the ability of shorts to "pile on" a stock in free fall, but doesn't eliminate selling pressure—it simply channels it to less aggressive price levels.

SSR applies only to short sales. Long holders selling their shares are unaffected. On a highly volatile stock where longs take massive profits, SSR won't prevent the pullback.

Where to read these numbers and how to verify them

All data used here comes from regulatory sources or directly verifiable records:

• Price and volume: public market data (tickers, order books, price histories), available via listing platforms (NASDAQ, NYSE, OTC Markets depending on listing venue).
• Float: calculated from 10-K (annual report), 10-Q (quarterly report), Schedule 13D/13G (positions > 5%), and Form 4 (insider transactions). These documents are freely accessible on SEC EDGAR.
• Dilution events: announced via 8-K (material event), S-1 or S-3 (offering registration), and 424B (final prospectus). These filings allow near real-time tracking of capital raises and warrant conversions that increase float.
• SSR: the list of stocks under SSR is published daily by exchanges (NASDAQ, NYSE) and publicly accessible.

FloatVerify's approach is to source and date every figure, and display divergences when multiple sources publish different floats at the same moment—the "source split" phenomenon. A float can vary by 10% or more between two aggregators depending on update date, inclusion or exclusion of exercisable warrants, and treatment of expired lockups. Displaying this divergence—rather than a single falsely certain figure—ensures the user has complete information to cross-check sources themselves.

Recap

Point	Takeaway
Most violent move	PFSA +597% intraday, +95% gap, 0.53M share float, 40.2M volume (76× float)
Tightest float	PFSA 0.53M shares; SLE 1.61M; SGLY 0.90M—micro-caps by free float market cap
Record volume-to-float	PFSA ~76×, SLE ~16.5×—extreme mechanical price pressure
Extreme gap	RCON +18,873% (near-zero prior close, resumption at $3.30)
Central mechanism	Tight float + concentrated volume = amplified volatility (up or down)
Regulatory sources	10-K/10-Q (total shares), 13D/13G (institutions > 5%), Form 4 (insiders), 8-K (dilution), SSR (exchange lists)
Invariant	Float is dated and changes with every dilution—verify measurement date

FAQ

What was the biggest small-cap gap on 2026-08-18?

PFSA (Profusa, Inc.) showed the highest intraday peak at +597%, with an opening gap of +95%. Measured float was 0.53 million shares, and volume reached 40.2 million trades—roughly 76 times the float. This volume-to-float ratio, combined with an extremely tight float, mechanically explains the magnitude of the move.

How does float influence gap amplitude?

Float represents the number of shares actually available for trading (excluding insiders, locked funds). When high volume concentrates on a low float, buying or selling pressure hits the price more violently. Each share traded carries proportionally more weight. A 0.53M float facing 40M volume mechanically creates extreme volatility, without predicting future direction.

Where do you find a small-cap's float in official documents?

Float is calculated from SEC forms: Form 10-K or 10-Q gives outstanding shares, Schedule 13D/13G details insider and institutional holdings above 5%, and Form 4 tracks insider transactions. You subtract locked positions from total outstanding to get effective float. This number changes with every dilution event—raise, warrant conversion, option exercise—hence the importance of the measurement date.

Why do some gaps show percentages above 100%?

A +133% gap (like IVF) means the opening price was 2.33 times the previous close. Gaps of several hundred percent typically appear after a very low close—sometimes just pennies—followed by renewed interest or a non-public catalyst. The extreme case of RCON (+18,873% gap) suggests a near-zero close the day before, followed by a technical resumption or quote correction.

What is the Short Sale Restriction (SSR) and when does it activate?

SSR (Regulation SHO Rule 201) prohibits aggressive shorts—selling at or below the bid—once a stock drops 10% or more from the prior close. It remains active through the close of the following day. On stocks that gap violently upward then retrace, SSR can trigger intraday if the drop from peak reaches 10% relative to the prior close, then limiting short selling pressure.

Sources

• SEC EDGAR: Forms 10-K, 10-Q, 8-K, S-1, S-3, 424B, Schedule 13D/13G, Form 4
• Regulation SHO Rule 201 (alternative uptick rule, SSR)
• SSR lists published daily by NASDAQ and NYSE
• Public market data (price, volume, order books) via listing platforms

See the float, sourced and dated, on FloatVerify.

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FloatVerify shows the float, dilution and cash burn of US small-caps, every number sourced and dated—and surfaces divergences between sources ("source split") instead of one falsely certain figure.

Disclaimer: FloatVerify is a data tool, not an investment advisory service. Nothing here is a recommendation to buy or sell. Data, not advice.