Understand VWAP-based intraday strategies — Stock-Market notes

WHY does VWAP exist?

WHAT problem it solves: A simple average of prices (e.g. average of every 1-minute close) treats a candle with 1 million shares the same as a candle with 100 shares. That's misleading — the 1-million-share candle is where real money changed hands. VWAP fixes this by weighting each price by its volume, so it reflects where the bulk of participation occurred.

WHY institutions care: A fund buying 500,000 shares can't dump the order at once. Their execution desk is graded on whether they bought at or below VWAP (for a buy) — beating VWAP means they got a better-than-average fill. This makes VWAP a self-reinforcing magnet: everyone watches it, so price often reverts toward it.

Deriving VWAP from scratch

We want the average price paid per share over the day. If $N$ trades happened:

Trade $i$ occurred at price $p_i$ with volume $v_i$ .
Money spent on trade $i$ = $p_i \cdot v_i$ .
Total money spent = $\sum_i p_i v_i$ .
Total shares = $\sum_i v_i$ .

Average cost per share = total money ÷ total shares:

Why divide by total volume, not by number of trades? Because we want a per-share average. Dividing by number of bars would give equal weight to each bar regardless of size — exactly the bias we're removing.

Why typical price $(H+L+C)/3$ ? A single bar traded across a range, not one price. $(H+L+C)/3$ is a cheap estimate of the bar's centre of mass since we don't have every tick.

VWAP Bands (standard-deviation envelopes)

To build strategies we add bands, like Bollinger Bands but around VWAP:

$\sigma = \sqrt{\frac{\sum_i v_i (p_i - \text{VWAP})^2}{\sum_i v_i}}$

Bands are drawn at $\text{VWAP} \pm k\sigma$ (often $k=1,2$ ). Price poking outside a band = statistically stretched → mean-reversion candidate.

Figure — Understand VWAP-based intraday strategies

The Core Strategies

Worked Examples

Worked example Example 1 — Computing VWAP by hand

Three 5-min bars on a stock:

Bar	H	L	C	Volume
1	102	98	100	1000
2	106	104	105	500
3	101	99	100	3000

Step 1 — typical prices. Why? We need one representative price per bar. $p_1=(102+98+100)/3=100$ , $p_2=(106+104+105)/3=105$ , $p_3=(101+99+100)/3=100$ .

Step 2 — $p_i v_i$ . Why? This is money spent per bar. $100·1000=100000$ , $105·500=52500$ , $100·3000=300000$ . Sum $=452500$ .

Step 3 — total volume. $1000+500+3000=4500$ .

Step 4 — divide. $\text{VWAP}=452500/4500 = 100.56$ .

Notice: Bar 2 traded at 105 but had tiny volume, so VWAP barely moved above 100. Bar 3's huge 3000-volume at 100 anchored VWAP down. That's the whole point of volume weighting.

Common Mistakes

Recall Feynman: explain to a 12-year-old

Imagine a whole day of kids buying candy. Some buy 1 candy, some buy 100. If you just averaged the prices on the labels, one kid who bought 1 expensive candy would count as much as the kid who bought 100 cheap ones — unfair! VWAP instead asks: "Add up ALL the money everyone spent, divide by ALL the candies bought." That gives the real average candy price for the day. Traders then say: if candy is selling above that fair price, it's a bit pricey (maybe it'll come back down); below it, it's a bargain. And because everyone uses the same fair-price line, prices keep getting pulled back toward it like a magnet.

Active Recall

What does VWAP stand for and what does it measure?

Volume-Weighted Average Price — the average price per share traded today, weighting each price by its volume.

Write the VWAP formula.

\text{VWAP} = \dfrac{\sum p_i v_i}{\sum v_i}

, with

p_i=(H_i+L_i+C_i)/3

, cumulative from the open.

Why weight by volume instead of averaging bar prices?

To get a true per-share average; equal-weighting biases toward low-liquidity bars that don't reflect where real money traded.

Why does VWAP get "stickier" through the day?

The denominator

\sum v_i

grows large, so each new bar barely moves the cumulative average.

Price above VWAP means what?

Buyers are in control (average buyer is paying up); bullish bias.

Reversion strategy: entry, target, when to use?

In a range: buy lower band / short upper band; target = VWAP. Use in non-trending markets.

Trend strategy: how is VWAP used?

As dynamic support/resistance — buy pullbacks to VWAP in an uptrend, short rallies to VWAP in a downtrend.

Why is regular VWAP useless on multi-day charts?

It resets each session; it only measures intraday participation. Use Anchored VWAP instead.

How are VWAP bands built?

\text{VWAP} \pm k\sigma

where

\sigma

is the volume-weighted std of typical price about VWAP.

Why is early-morning VWAP unreliable?

Tiny cumulative volume makes it jumpy; a single large trade swings it.

Connections

Volume analysis — VWAP is a volume-weighted derivative of price.
Bollinger Bands — same $\pm k\sigma$ envelope idea, different centre line.
Mean Reversion vs Trend Following — VWAP feeds both regimes.
Anchored VWAP — the multi-day generalization.
Support and Resistance — VWAP acts as dynamic S/R.
Institutional Order Execution — why VWAP is a benchmark at all.
Typical Price (HLC/3) — the per-bar price input.

Concept Map

Hinglish (regional understanding)

Intuition Hinglish mein samjho

Dekho, VWAP ka matlab hai Volume-Weighted Average Price — yaani din bhar mein stock ka actual average price jo logon ne pay kiya, lekin har price ko uske volume ke hisaab se weight karke. Simple average galat hota hai kyunki jahaan 10 lakh shares trade huye aur jahaan sirf 100 shares — dono ko barabar count kar deta. VWAP bolta hai: total paisa (price × volume) jodo, aur total shares se divide karo. Isse pata chalta hai ki "asli" fair price kya thi jahaan bada paisa move hua.

Yeh line intraday traders ke liye ek magnet ki tarah kaam karti hai. Bade funds ko grade kiya jaata hai ki unhone VWAP se neeche khareeda ki nahi — isliye poori duniya isko dekhti hai, aur price baar-baar VWAP ki taraf khinchti hai. Ek simple rule: price VWAP ke upar hai matlab bulls ka control (bullish), neeche hai matlab bears ka control (bearish), aur exactly upar ho toh fair value.

Do main strategy yaad rakho. Pehli — Reversion: jab market side-ways/range mein ho, price agar +2σ band tak spike kare toh short, -2σ tak gire toh buy, target hamesha VWAP. Doosri — Trend pullback: agar market ek taraf trend kar raha ho aur VWAP ke upar hi tik raha ho, toh jab price wapas VWAP tak aaye (pullback) tab buy karo, stop VWAP ke thoda neeche. Sabse badi galti: dono strategy opposite hain — trend mein reversion mat khelo warna nuksan pakka. Aur yaad rakho VWAP har din reset hota hai, subah ke pehle minutes mein volume kam hone se yeh line bahut jumpy rehti hai, thoda settle hone do.

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Connections