I need all stocks that about to halt?

Important Context

Whether a stock is about to be halted cannot be known or guaranteed in advance. Trading halts are imposed by exchanges or regulators, often suddenly, due to volatility, pending news, compliance issues, or other events.

What we can do is screen for stocks that exhibit conditions commonly present before or around halts: very sharp moves, unusual volume, and significant news catalysts. That’s what these filters are trying to approximate.

Screening Filters

1. list_exchange: ['XNYS', 'XNAS', 'XASE']

   • Purpose: Limit the universe to major U.S. exchanges: NYSE, NASDAQ, and NYSE American.
   • Rationale:
     • The user asked for “stocks in the US market,” so this ensures results are U.S.-listed equities on the main exchanges where trading halts are systematically reported and governed by well-defined rules (e.g., Limit Up/Limit Down volatility halts).
     • Excludes OTC, pink sheets, and foreign exchanges that might have different halt rules or less transparent halt data.

2. price_change_pct: {'min': '-100', 'max': '-8'}

   • Purpose: Find stocks that have fallen sharply intraday (down more than 8%, up to a theoretical -100%).
   • Rationale:
     • Abrupt, large price drops often precede or coincide with volatility halts or news-related halts.
     • A decline worse than -8% captures names that are under severe selling pressure, which is where you most often see halts due to extreme volatility or pending material news.
     • Setting min at -100 is effectively just a technical lower bound (a stock can’t drop more than -100%); the real intent is to capture all extremely negative moves from -8% downward.

3. relative_vol: {'min': '1.5'}

   • Purpose: Require unusually high trading activity, at least 1.5× the stock’s typical volume.
   • Rationale:
     • Trading halts are frequently associated with surges in trading volume—either because of breaking news or panic buying/selling.
     • A relative volume ≥ 1.5 flags abnormal interest/pressure in the stock compared with its normal behavior, which often goes hand-in-hand with halt-prone scenarios (rapid order imbalances, big price gaps, volatility spikes).
     • This helps distinguish routine -8% moves in thinly traded names from high-attention, high-activity situations more likely to trigger or accompany a halt.

4. news_driver: ['Positive', 'Negative']

   • Purpose: Focus on stocks where recent news is identified as a key driver of the current move (positive or negative).
   • Rationale:
     • Many halts occur around material news events (earnings surprises, M&A, FDA decisions, investigations, etc.), where exchanges pause trading to allow dissemination of information.
     • By requiring a news driver, we target stocks whose big price/volume moves are linked to specific, potentially halt-related catalysts, not just random drift or technical noise.
     • Including both “Positive” and “Negative” acknowledges that halts can occur on good news (e.g., takeover offers, breakthrough approvals) as well as bad news (e.g., fraud allegations, massive guidance cuts).

Why the Results Match the User’s Intent

• The exchange filter aligns the universe with the U.S. market, matching your geographical requirement.
• The large negative price change and elevated relative volume together identify extreme, abnormal trading conditions, where volatility and order imbalance are at levels that historically see more halts.
• The news driver filter homes in on news-sensitive situations, which are a common trigger or context for trading halts as exchanges allow investors time to absorb significant information.

Combined, these filters do not guarantee that the stocks are “about to halt,” but they systematically surface U.S.-listed names under intense pressure and news-driven stress, which are the types of conditions most associated with imminent or recent trading halts.