Ek bada sell order (ya fat-finger error, ya algo bug) ek aise market mein aata hai jisme thin liquidity hoti hai.
Price girta hai. Stop-loss orders automatically trigger ho jaate hain → woh market sell orders ban jaate hain → aur selling hoti hai.
Market makers (HFT firms) abnormal volatility dekhte hain aur spreads widen kar dete hain ya apne quotes pull kar lete hain taaki run over hone se bache. Ab almost koi bids hain hi nahi.
Bids ke jaane ke baad, chhoti si selling bhi price ko aur neeche crash kar deti hai. Feedback loop chillaata hai.
Price absurd levels par pahunch jaati hai (stub quotes jaise $0.01 ya $100,000).
Socho ek bheed wale kamre mein sab log ek saath "SELL!" chillaane lage aur darwaze ki taraf bhaagne lage — woh ek doosre ko girate hain aur panic failti jaati hai. Ek flash crash wahi bhagdad hai, lekin prices ke saath. Ek circuit breaker ek teacher hai jo chillaata hai "FREEZE — sab 15 minutes ke liye ruko!" Log shant ho jaate hain, realize karte hain ki aag asli nahi thi, aur safely bahar nikal jaate hain. Freeze kamre ko theek nahi karta; yeh sirf trampling itni der ke liye rokta hai taaki common sense wapas aa sake.
Price drop → stop-losses trigger + market makers quotes pull karte hain → kam liquidity → bada drop.
Circuit breaker kya hota hai?
Ek pre-set rule jo automatically trading halt/slow karta hai jab price ek threshold se zyada move kare, panic loop todne ke liye.
US ke teen market-wide circuit breaker levels kya hain?
S&P 500 7% neeche (L1, 15-min halt), 13% (L2, 15-min halt), 20% (L3, baaki din ke liye halt).
Market-wide breakers declines par trigger kyun hote hain, rallies par nahi?
Kyunki panic selling hi destabilising feedback loop hai; rallies usi tarah ki liquidity-collapse spiral produce nahi karti.
LULD kya hai?
Limit Up–Limit Down: ek stock ke 5-min average ke aaspaas ek symmetric price band jo trading pause kar deta hai agar price ≥15 s tak bahar rahe.
P_ref=50, b=5% ke saath LULD band formula?
Upper 52.50, Lower 47.50 (P_ref·(1±b)).
Flash crash usually fast recover kyun karta hai?
Yeh ek liquidity event hai, value change nahi; ek baar forced selling exhaust hone par, sasti prices real buyers ko attract karti hain.
Stop-loss flash crash mein tumhein hurt kyun kar sakta hai?
Yeh stop par market order mein convert ho jaata hai, toh stub price par fill ho sakta hai jo intended se bahut neeche hai, aur yeh selling cascade mein add bhi karta hai.
Kya circuit breaker price floor set karta hai?
Nahi — yeh sirf trading pause karta hai; halt ke baad price phir bhi gir sakti hai.
