1.6.12
Ek Level-1 quote order book ka sabse patla slice hota hai jo aap dekh sakte ho: yeh tumhe best bid , best ask , last traded price , aur in dono best prices par kitni size baithe hai — yeh sab batata hai. Socho jaise do queues ke aage dekh rahe ho — kharidne wali crowd (bid) aur bechne wali crowd (ask) — lekin sirf har line ke sabse aage khade insaan ko, poori line ko nahi.
WHY it exists: har trade buyers aur sellers ke beech ek negotiation hai. Level-1 tumhe uss negotiation ki current agreed boundary (spread) deta hai, plus woh price jis par last handshake actually hua.
Definition Level-1 fields
Bid = highest price joh ek buyer abhi pay karne ko ready hai .Ask (a.k.a. Offer) = lowest price joh ek seller abhi accept karne ko ready hai .Bid Size = shares ki number jo best bid par available hai.Ask Size = shares ki number jo best ask par available hai.Last = most recent completed trade ki price.Volume = session mein ab tak total traded shares (cumulative).
Sabse important derived quantity hai spread .
cost kyun hai
Agar tum market buy karo toh Ask pay karte ho; agar turant market sell karo toh Bid milta hai. Spread turant loss ho jaata hai. Toh spread abhi liquidity demand karne ki price hai. Wide spread = illiquid / risky; tight spread = liquid / crowded.
Ek raw Level-1 line aksar aisi dikhti hai:
XYZ Bid 100.20 x 500 Ask 100.24 x 300 Last 100.22 Vol 1,240,000
Isse aise padho: "Best buyers 100.20 pay karenge up to 500 shares ke liye; best sellers 100.24 chahte hain 300 shares ke liye; last trade 100.22 par print hua; 1.24 M shares aaj hands change kar chuke hain."
Worked example Example 3 — size imbalance padhnaBid 50.00 × 10,000 | Ask 50.02 × 400.
Bid size (10,000) ≫ Ask size (400). Yeh kyun matter karta hai? Heavy buying interest vs thin selling → halka upward pressure ka hint. Yeh step sirf hint kyun hai: sizes instantly spoof/cancel ho sakti hain; weak evidence maano, signal nahi.
Recall Pehle predict karo, phir neeche check karoQuote: Bid 250.10 × 200 | Ask 250.50 × 200 | Last 250.30.
Spread aur mid forecast karo.
Yeh stock likely liquid hai ya illiquid?
Verify: Spread = 0.40 = 250.30 = 0.40/250.30 ≈ 0.16% wide hai → illiquid/lower volume ki taraf jhukta hai. Notice karo Last yahan Mid par baitha hai (ek trade just fair value ke paas cross hua).
Common mistake "Last price wahi price hai jo main pay karunga."Kyun sahi lagta hai: Last sabse bada, sabse bold number hota hai zyaadatar screens par, aur yeh ek real trade hai. Kyun galat hai: Last history hai — already ho chuka. Tumhara order current Bid/Ask ke against fill hota hai, jo move kar sakta hai. Fix: kharidne ke liye Ask dekho; bechne ke liye Bid dekho. Last sirf ek sanity check hai.
Common mistake "Bada bid size matlab price ZAROOR upar jayegi."Kyun sahi lagta hai: zyaada buyers chahiye price upar push karna. Kyun galat hai: Level-1 size ek snapshot hai; orders milliseconds mein cancel/add hote hain, aur bade orders deliberately fake ho sakte hain (spoofing). Fix: size ko weak context ki tarah use karo, kabhi standalone trade trigger ki tarah nahi.
Common mistake "Mid woh price hai jis par trades hoti hain."Kyun sahi lagta hai: yeh "fair middle" hai. Kyun galat hai: market order ke saath tum Bid ya Ask par cross karte ho, Mid par nahi. Sirf kuch limit/midpoint orders Mid par execute hote hain. Fix: Mid = reference value; execution = Bid ya Ask (jab tak special order type na ho).
Level-1 quote mein Bid kya hota hai? Highest price jo ek buyer abhi pay karne ko willing hai.
Ask/Offer kya hota hai? Lowest price jo ek seller abhi accept karne ko willing hai.
Spread ka formula? Spread = Ask − Bid.
Midpoint ka formula? Mid = (Bid + Ask) / 2.
Jab tum MARKET BUY karte ho, kaunsi price pay karte ho? Ask (best offer).
Jab tum MARKET SELL karte ho, kaunsi price milti hai? Bid (best buy price).
Spread ko cost of liquidity kyun kehte hain? Ek immediate round trip (Ask par kharido, Bid par becho) tumhe spread lose karata hai; yeh abhi trade karne ki price hai.
"Last" tumhe kya batata hai aur iska limitation kya hai? Most recent completed trade ki price; yeh historical hai aur zaroors tumhari fill price nahi hogi.
Bid/ask SIZE ka kya matlab hai, aur ise cautiously kyun treat karo? Best bid/ask par available shares; yeh instantly cancel ya spoof ho sakti hai, isliye weak evidence hi hai.
WIDE spread % usually kya indicate karta hai? Lower liquidity / higher trading cost / thinner interest.
Kya Level-1 tumhe bade order par "walking the book" ke baare mein warn kar sakta hai? Nahi — Level-1 sirf book ka top dikhata hai; deeper prices ke liye Level-2 chahiye.
Recall Feynman: ek 12-saal ke bacche ko explain karoEk toy market imagine karo. Ek taraf, bacche sabse zyaada pay karne ki offer chillate hain sticker ke liye — sabse unchi offer hai Bid . Doosri taraf, bacche sabse kam mein sell karne ki offer chillate hain — sabse sasti hai Ask . "Main 20 pay karunga" aur "Main 22 mein bechunga" ka gap hai spread . Agar tumhe abhi sticker chahiye, toh seller ko 22 pay karo; agar abhi bechna hai, toh buyer ka 20 lo. Last number sirf woh price hai jis par pichle bacche ne actually trade ki — purani baat. Yahi hota hai ek poora Level-1 quote!
Mnemonic Fields yaad karo"BALLS + V" → B id, A sk, L ast, L ots(sizes), S pread, aur V olume. Aur rule yaad raho: "Buy the Ask, Sell the Bid, Last is dead."
Order Types & Mechanics Market Order vs Limit Order Bid-Ask Spread as Transaction Cost Level-2 Market Depth — Level-1 ke peeche poori queueLiquidity and Slippage Walking the Book Order Book Basics
