Understand gap trading (gap up - down - fill)

4.6.5 · Stock-Market › Trading Strategies

Gap KYA hota hai?

Gap exist kyun karta hai? Kyunki ek stock chart executed trades ka record hai. 3:30 PM close aur 9:15 AM open ke beech, koi trade execute nahi hota — lekin buy/sell pressure accumulate hota rehta hai (earnings, global markets, policy). Opening auction par, sara pressure ek naye price mein resolve hota hai. Agar wo price kal ke close se kaafi door hai, to ek visible khali band dikhti hai = the gap.

Gap kitna bada hai? (Measure ko scratch se derive karo)

Hame EK number chahiye jo bole "ye open kitna surprising hai?"

Step 1 — Raw gap size. Sabse simple measure sirf jump ki distance hai: $G = O_{t} - C_{t - 1}$ jahan $O_{t}$ = aaj ka open, $C_{t - 1}$ = kal ka close. Ye step kyun? Price literally $C_{t - 1}$ se $O_{t}$ tak beech mein kuch nahi hue move kiya, isliye unka difference hole ki size hai.

Step 2 — Ise stocks ke beech comparable banao. ₹5 gap ek ₹5000 stock par kuch nahi maayta lekin ₹50 stock par sab kuch. Isliye hum previous close se normalize karte hain: $G % = \frac{O _{t} - C _{t - 1}}{C _{t - 1}} \times 100$ Ye step kyun? Price se divide karne par rupaye ek percentage mein convert ho jaate hain, isliye Reliance par ek gap aur ek penny stock par ek gap ek hi language bolte hain.

Step 3 — Judge karo ki ye "real" hai ya nahi. Gap ko stock ki normal daily wiggle (Average True Range, ATR) se compare karo. Ek significance ratio define karo: $R = \frac{∣ O _{t} - C _{t - 1} ∣}{ATR _{14}}$ Ye step kyun? Agar gap ek typical din ki range se chhota hai, to ye sirf noise hai. Agar $R > 1$ hai, to price usually poore ek din mein jitna move karti hai usse zyada jump kiya — ye ek meaningful gap hai jo trade karne layak hai.

Figure — Understand gap trading (gap up - down - fill)

Char gap "personalities" (WHY ve alag behave karte hain)

Type	Setup	Typical behavior
Common gap	recent range ke andar, low volume	jaldi fill hota hai — fade it
Breakaway gap	prior range se bahar khulta hai, consolidation se bahar, HIGH volume	rarely fill hota hai — trend start hota hai
Runaway (continuation) gap	mid-trend, trend direction mein	continuation, partial fill
Exhaustion gap	ek lambe move ke baad, huge volume	trend ends, reverses & fills

Do core strategies

A. Gap-and-Go (momentum): ek strong, high-volume gap ki direction mein enter karo jab price pehli 5-min candle ke high (gap up) / low (gap down) ko break kare. Bet: jump justified tha, trend continue karega.

B. Gap-Fill (fade / mean-reversion): ek weak, low-volume gap ke against enter karo, yesterday's close ko target karke. Bet: over-reaction wapas snap back karega.

Worked Examples

Common Mistakes (Steel-man → Fix)

Recall Feynman: 12-saal ke bachche ko samjhao

Ek video game imagine karo jo raat bhar paused hai. Paused hone ke dauran, sab log achhi ya buri news chillaate hain. Jab tum subah play press karte ho, tumhara character wahan teleport ho jaata hai na ki walk karta — wo khali jumped-over space hi gap hai. Hum ise wahan se measure karte hain jahan character sone ke waqt khada tha (kal ka close), na ki usne jo sabse door step uthaya wahan se. Agar bahut logon ne sach mein maana (loud = high volume), character wahi reh jaata hai. Agar ye sirf ek bachcha tha jo overreact kar raha tha, to character usually sone ki jagah wapas chal ke jaata hai — wo wapsi hi gap fill hai.

Flashcards

Price chart mein gap kya hota hai?

Ek price region jahan koi trades nahi hue, tab banta hai jab aaj ka open kal ke close se alag ho.

Gap define karne ka reference level kya hai?

Kal ka close (kal ka high/low nahi).

Gap up define karo.

Aaj ka open kal ke close se upar hota hai (

O_{t} > C_{t - 1}

Gap down define karo.

Aaj ka open kal ke close se neeche hota hai (

O_{t} < C_{t - 1}

Gap fill kya hota hai?

Price kal ke close tak wapas trade karti hai, khali gap region ko band karke.

Kaun sa gap type poori prior day ki range se bahar khulta hai?

Breakaway (full) gap — stronger, out-of-range case, general definition nahi.

Percent gap size ka formula?

G % = \frac{O _{t} - C _{t - 1}}{C _{t - 1}} \times 100

Significance ratio kya hai aur gap kab tradable hota hai?

R = ∣ O_{t} - C_{t - 1} ∣/ ATR_{14}

; tradable jab

R ≳ 1

Kaun sa gap type usually holds karta hai aur fill nahi hota?

Breakaway gap (high volume, prior range se bahar khulta hai).

Kaun sa gap type reliably same day fill hota hai?

Common gap (low volume, range ke andar).

Gaps ke liye volume rule of thumb?

High volume → gap holds (ride/gap-and-go); low volume → gap fills (fade).

Gap up fade karne ka Reward/Risk?

(O_{t} - C_{t - 1}) / (H_{t} - O_{t})

; sirf tabhi lo jab

\geq 2

ho.

Exhaustion gap ki kya signals hoti hain?

Huge volume par ek lambe trend ke baad ek gap jo phir reverse karke fill hota hai.

Connections

Support and Resistance — kal ka close fill target/magnet ki tarah kaam karta hai.
Average True Range (ATR) — gap significance judge karne ke liye use hota hai.
Volume Analysis — hold vs fill ka lie-detector.
Breakout Trading — breakaway gaps gap-based breakouts hain.
Risk-Reward and Position Sizing — fades ke liye stop aur R:R set karta hai.
Opening Range Breakout — gap-and-go mein pehli 5-min candle use hoti hai.